The Diamond Certification Laboratory of Australia (DCLA)

The Calf’s Head Diamond is a historic and notable diamond that is part of British royal history. It has a distinctive shape and was owned by several prominent figures over the centuries.

Key Facts About the Calf’s Head Diamond:
Appearance and Characteristics

The Calf’s Head Diamond is known for its unique shape, which is said to resemble the head of a calf. It is a fancy-shaped diamond, with its unusual appearance contributing to its historical and cultural significance.
It is reported to have a yellowish or light brown hue, adding to its distinctiveness compared to the more typical clear diamonds.
Historical Background

This diamond has been part of the British royal collection and is known to have passed through various notable hands.
It was famously owned by King Charles II of England. During his reign, it was said to be part of the crown jewels.
Symbolism and Significance

The Calf’s Head Diamond is believed to symbolize wealth, nobility, and royalty due to its connection to the monarchy.
The diamond’s unusual shape and connection to the English monarchy have made it a subject of historical intrigue.
Current Status

The location of the Calf’s Head Diamond today is uncertain, and its current whereabouts are not widely known, adding to the mystery surrounding this remarkable gem.

A Canary Diamond is a highly sought-after type of fancy yellow diamond known for its rich, intense yellow hue. These diamonds get their vibrant colour from the presence of nitrogen, which absorbs blue light and allows yellow to be the dominant visible colour.

Key Features of Canary Diamonds:
Intense Yellow Colour

Unlike lower-grade yellow diamonds, canary diamonds exhibit a deep, pure yellow shade with strong saturation.
The term “canary” is an unofficial trade name used to describe Fancy Intense Yellow or Fancy Vivid Yellow diamonds, the highest-quality yellow diamonds.
Rarity and Value

Fancy yellow diamonds make up only a small percentage of mined diamonds, and the Fancy Vivid Yellow variety (the purest canary shade) is even rarer.
Their value depends on colour intensity, carat weight, clarity, and cut.
Grading by the GIA

The Gemological Institute of America (GIA) classifies yellow diamonds into different intensities:
Faint Yellow
Very Light Yellow
Light Yellow
Fancy Light Yellow
Fancy Yellow
Fancy Intense Yellow (Canary Diamond Category)
Fancy Vivid Yellow (Most Valuable Canary Diamonds)
Famous Canary Diamonds

The Tiffany Yellow Diamond (128.54 carats) – One of the world’s largest and most famous canary diamonds, owned by Tiffany & Co.
The Allnatt Diamond (101.29 carats) – A renowned Fancy Vivid Yellow diamond.
Investment Potential

Due to their beauty, rarity, and growing demand in the luxury jewelry market, high-quality canary diamonds are considered an excellent investment.

A broad scale of diamond colour grades that ranges from a near colourless, almost undetectable pale yellow to increasingly tinted yellow. Once it has enough yellow saturation to qualify as a fancy colour, it is no longer called a Cape Series diamond.

Cape Series Diamonds refer to a category of diamonds that exhibit a noticeable yellow or brown tint due to the presence of nitrogen in their crystal structure. The term originates from the Cape Province of South Africa, where these diamonds were historically mined in large quantities.

Characteristics of Cape Series Diamonds:
Colour Range

These diamonds fall within the near-colourless to light yellow range on the GIA D–Z colour scale.
They typically appear in the K to M range, but some can extend beyond, showing a deeper yellow tint.
Unlike Fancy Yellow Diamonds (such as Canary Diamonds), Cape Series Diamonds do not have the intense saturation needed to be classified as “fancy colour diamonds.”
Cause of Yellow Tint

The yellowish hue comes from nitrogen impurities, which absorb blue light and make the diamond appear slightly yellow.
The higher the nitrogen concentration, the stronger the yellow tint.
Historical Significance

The name “Cape Series” comes from South Africa’s Cape Province, where many of these diamonds were first discovered in the late 19th century.
These diamonds were highly valued in the early days of diamond mining, especially before the discovery of purer, colourless diamonds.
Market Perception & Value

Higher Colour Grades (K–M): Often sold at a discount compared to colourless diamonds (D–F), making them an affordable option for buyers.
Lower Grades (N–Z): Can exhibit a stronger yellow tone, appealing to those who prefer warm-toned diamonds.
Well-cut Cape Series Diamonds can still appear brilliant, especially in round brilliant and cushion cuts, which minimize visible colour.
Modern Use

Many Cape Series Diamonds are set in yellow gold settings to enhance their warmth and reduce contrast.
Some are reclassified as “faint yellow” fancy diamonds if their colour saturation is strong enough.

Key Facts About Carat Weight:
Definition

One carat is equal to 200 milligrams (0.2 grams).
It is subdivided into 100 points, meaning a 0.50-carat diamond is also called a 50-point diamond.
Origin of the Term

The term “carat” comes from the carob seed, which was historically used as a reference for weighing gemstones due to its uniform weight.
Carat vs. Size

While carat refers to weight, it does not always indicate a diamond’s physical size.
Different cuts and shapes can make a diamond appear larger or smaller than another of the same weight.
Impact on Price

Diamond prices increase significantly with carat weight, especially at milestone sizes (e.g., 0.50 ct, 1.00 ct, 1.50 ct, 2.00 ct).
Larger diamonds are rarer and more expensive per carat than smaller ones.
Carat Weight vs. Other Cs

A diamond’s cut, colour, and clarity also play a major role in its overall value and appearance.
A well-cut 0.90-carat diamond can appear nearly the same size as a 1.00-carat diamond but at a lower cost.

Diamonds are made of pure carbon, but their unique atomic structure is what gives them their remarkable properties.

Why Diamonds Are Special:
Pure Carbon Composition

Diamonds are composed entirely of carbon atoms (C) arranged in a crystal lattice structure.
Unlike other carbon-based materials like graphite or coal, diamonds have a tetrahedral atomic arrangement, making them the hardest naturally occurring substance.
Crystal Structure: The Secret to Hardness

Each carbon atom in a diamond forms strong covalent bonds with four other carbon atoms in a three-dimensional network.
This cubic crystal structure (known as a diamond cubic lattice) gives diamonds their exceptional hardness and durability.
Difference from Graphite

Both diamond and graphite are made of pure carbon, but they have different atomic structures (allotropes):
Diamond: Carbon atoms are arranged in a rigid 3D tetrahedral network → Hard and transparent
Graphite: Carbon atoms are arranged in stacked layers of hexagonal sheets → Soft and opaque
This difference in structure explains why diamond is used in cutting tools while graphite is used in pencils.
Formation Process

Natural diamonds form under high temperature (1,000–1,300°C) and extreme pressure (45–60 kbar) deep within the Earth’s mantle over 1–3 billion years.
Lab-grown diamonds are created using HPHT (High Pressure High Temperature) or CVD (Chemical Vapor Deposition) methods, replicating these natural conditions.
Purity and Impurities

A pure diamond consists only of carbon, but trace elements (e.g., nitrogen, boron) can cause variations in colour:
Nitrogen → Yellow diamonds
Boron → Blue diamonds
Radiation exposure → Green diamonds

Small black graphite inclusions in a diamond are a type of natural impurity that occurs during the diamond’s formation process. These inclusions can affect the diamond’s clarity, appearance, and value.

Key Facts About Black Graphite Inclusions in Diamonds:
What Are They?

Black inclusions are tiny particles of graphite or other carbon-based minerals trapped inside the diamond during its crystallization.
They appear as small black spots, specks, or clusters within the stone.
Impact on Clarity & Value

Diamonds with large, visible graphite inclusions receive lower clarity grades from the GIA (Gemological Institute of America).
If the inclusions are numerous or positioned near the surface, they can reduce transparency and brilliance.
However, some graphite inclusions are microscopic and do not impact the stone’s beauty significantly.
Types of Graphite Inclusions

Pinpoints – Tiny black dots only visible under magnification.
Clouds – Groups of small inclusions that create a hazy effect.
Needles or Veins – Thin, elongated graphite inclusions.
Carbon Spots – Larger black inclusions visible to the naked eye.
Are They a Problem?

If inclusions are small and well-placed (e.g., near the edges), they may not significantly affect the diamond’s beauty.
However, large or centrally located inclusions can impact transparency, sparkle, and durability.
How to Minimize Their Appearance

Cut Quality Matters – A well-cut diamond with a brilliant faceting pattern (e.g., round brilliant) can hide inclusions.
Setting Choice – Prongs and bezels can mask inclusions near the edges.
Clarity Enhancement – Some diamonds undergo laser drilling or fracture filling to reduce the visibility of black inclusions.

A cavity is a type of diamond inclusion that appears as an opening or large indentation on the surface of a diamond. It occurs when a small part of the diamond is removed, often due to the detachment of another inclusion (such as a crystal or feather) during the cutting or polishing process.

Key Characteristics of Cavity Inclusions in Diamonds:
How Cavities Form

They usually form when a weak area of the diamond, such as an internal inclusion, falls out during cutting, polishing, or wear.
Can also result from the removal of a feather (crack) or crystal inclusion.
Impact on Diamond Quality & Value

Visibility: Cavities can be noticeable, especially if they are large or located in a prominent position.
Durability Concern: A deep cavity can make a diamond more vulnerable to chipping or further damage over time.
Clarity Grade Reduction: Diamonds with significant cavities may receive a lower clarity grade from the GIA (Gemological Institute of America).
Where Cavities Are Found

They can appear anywhere on the diamond, but those near the edges or girdle are less concerning than those in the center (table).
How to Minimize the Effect of Cavities

Strategic Setting: A prong or bezel setting can hide a cavity located near the edge.
Polishing & Recutting: If the cavity is shallow, a jeweler may be able to polish or recut the diamond to remove or reduce its appearance.
Avoiding Further Damage: Regular cleaning and careful handling can help prevent dirt from accumulating inside the cavity, which can make it more visible.

Diamond Certificate or Diamond Report
A diamond certificate, also known as a diamond grading report, is an official document issued by a gemological laboratory that provides an objective assessment of a diamond’s quality. It evaluates key characteristics such as carat weight, cut, colour, clarity, and other essential factors.

What a Diamond Certificate Includes:
A diamond grading report typically contains:

Carat Weight – The precise weight of the diamond in carats (ct).
Cut Grade – Evaluates how well the diamond is cut, affecting its brilliance and fire.
Colour Grade – Ranges from D (colourless) to Z (light yellow or brown).
Clarity Grade – Assesses internal inclusions and external blemishes, from Flawless (FL) to Included (I3).
Shape & Measurements – Specifies the diamond’s shape (e.g., round, oval) and dimensions in millimeters.
Fluorescence – Indicates if the diamond glows under UV light, which may impact its appearance.
Symmetry & Polish – Evaluates the precision of the diamond’s cut and surface quality.
Inclusion Plot (Clarity Map) – A diagram showing the locations of inclusions and blemishes.
Security Features – Some certificates include laser inscription of the report number on the diamond’s girdle for verification.
Recognised Diamond Certification Laboratories
Reputable gemological laboratories that provide independent, accurate, and unbiased diamond grading include:

GIA (Gemological Institute of America) – The most respected and widely recognised grading authority worldwide.
AGS (American Gem Society) – Known for its strict grading standards, particularly for cut quality.
HRD (Hoge Raad voor Diamant) – A leading European gem lab based in Antwerp, Belgium.
IGI (International Gemological Institute) – Commonly used in the retail diamond market.
EGL (European Gemological Laboratory) – Offers looser grading standards compared to GIA and AGS.
DCLA (Diamond Certification Laboratory of Australia) – The only independent diamond grading laboratory in Australia, known for its strict and accurate grading.

Key Characteristics of Chameleon Diamonds:
Colour Change:

Chameleon diamonds typically shift from an olive green or grayish-green hue to a yellow or orangey-yellow shade when exposed to heat (approximately 150°C) or left in darkness for an extended period.
Once cooled or exposed to light again, they revert to their original colour.
Thermochromic & Photochromic Properties:

The colour change can occur due to both heat (thermochromism) and darkness/light exposure (photochromism), making them unique among diamonds.
Rare Chemical Composition:

Scientists believe the colour change is due to a combination of hydrogen, nitrogen, and possibly nickel impurities within the diamond’s crystal structure.
Not a Fancy Colour Diamond:

Unlike standard fancy colour diamonds, which have a fixed hue, chameleon diamonds possess a dynamic, temporary colour change.
Value & Rarity:

Due to their scarcity, chameleon diamonds are highly prized by collectors and diamond enthusiasts.

Unlike standard fancy colour diamonds, which have a fixed hue, chameleon diamonds possess a dynamic, temporary colour change.

Value & Rarity:

Due to their scarcity, chameleon diamonds are highly prized by collectors and diamond enthusiasts.

Champagne Diamonds: A Unique Fancy-Coloured Diamond
A champagne diamond is a type of fancy-coloured diamond that exhibits a warm brown hue with subtle golden or yellow undertones, resembling the colour of champagne. These diamonds are prized for their unique earthy tones and affordability compared to traditional white diamonds.

Key Characteristics of Champagne Diamonds
Colour Range

Champagne diamonds range from light golden brown to deep cognac shades.
The colour intensity is determined by the presence of nitrogen in the diamond’s structure.
The Argyle Mine in Australia (now closed) famously produced some of the world’s finest champagne diamonds.
Grading & Classification
Unlike white diamonds, which are graded on the D-Z colour scale, champagne diamonds are classified based on their intensity:

C1 – C2: Light champagne
C3 – C4: Medium champagne
C5 – C6: Dark champagne
C7: Deep brown (also called Cognac Diamond)
Cut & Shape

Champagne diamonds are cut in various shapes, with round, oval, cushion, and pear cuts being popular.
A well-cut champagne diamond enhances its brilliance and highlights its warm tones.
Rarity & Value

While not as rare as pink or blue diamonds, high-quality champagne diamonds with strong brilliance and even colour distribution are highly sought after.
They are generally more affordable than traditional colourless diamonds, making them an attractive alternative.
Symbolism & Popularity

Champagne diamonds symbolize elegance, warmth, and individuality.
They are increasingly popular in engagement rings and bespoke jewellery due to their distinct and sophisticated look.

A chipped diamond refers to a diamond that has sustained a small break or loss of material from its surface, typically at the edges or corners. Chipping is generally caused by impact or rough handling. While it may not affect the diamond’s overall structure, it can influence its appearance, value, and durability.

Key Points About Chipped Diamonds:
Causes of Chipping:

Impact: Diamonds are very hard but not immune to damage, especially if they experience a sudden blow or fall onto a hard surface.
Sharp Edges: Diamonds with sharper corners or thinner edges, such as those found in princess cuts or emerald cuts, are more prone to chipping.
Improper Setting: A diamond set in a way that leaves its edges exposed is at higher risk of chipping.
Impact on Value and Appearance:

Clarity: A chipped diamond may have a noticeable blemish that lowers its clarity grade. It can reduce the diamond’s brilliance, as light may not reflect as effectively from the damaged area.
Aesthetic: A chip is visible to the naked eye in most cases, especially if it’s located near the centre or on a large diamond.
Value: Chipped diamonds are typically worth less than those without damage. The degree of value loss depends on the size and location of the chip.
Repair Options:

Re-cutting: For diamonds with significant chips, a jeweler can re-cut the diamond to remove the damaged area, potentially enhancing the diamond’s overall appearance. However, this reduces the diamond’s carat weight.
Polishing: Small chips can sometimes be smoothed or polished to reduce visibility, though this may not completely eliminate the blemish.
Re-setting: If the chip is near the edge, a jeweler may also re-set the diamond in a protective setting, such as a bezel, to prevent further damage.
Prevention:

Careful Handling: To prevent chipping, diamonds should be handled carefully, especially if set in rings or worn frequently.
Secure Setting: Settings that protect the edges of the diamond, such as bezel or tension settings, can prevent damage.
Checking for Chips:

It’s essential to regularly inspect your diamond for any signs of damage, especially after a fall or impact. A professional inspection can also reveal chips that may not be easily noticeable with the naked eye.

CIBJO, also known as The World Jewellery Confederation, is a global organization that represents the jewellery industry. It brings together national jewellery trade associations from around the world to establish standards of practice, ethical guidelines, and global cooperation in the jewellery sector.

Key Facts About CIBJO (The World Jewellery Confederation):
Purpose and Mission

CIBJO’s mission is to unite national jewellery organizations to promote the interests of the global jewellery industry, while setting standards for quality, trade practices, and ethical business in the jewellery sector.
The confederation aims to ensure transparency in the jewellery trade and foster sustainable business practices while safeguarding the reputation of the industry.
Membership

CIBJO’s membership consists of national jewellery trade associations from various countries, including major players like India, the United States, Italy, and Australia.
It represents the interests of manufacturers, wholesalers, retailers, and other professionals in the jewellery supply chain.
Key Functions and Activities

Establishing Standards: CIBJO works to develop uniform standards for the jewellery industry, including the grading and certification of diamonds and coloured gemstones, and the ethical sourcing of materials.
Ethical Guidelines: The organization promotes ethical practices in the jewellery trade, ensuring that jewellery businesses operate with transparency, integrity, and responsibility.
Advocacy: CIBJO advocates for the interests of the jewellery industry at international trade bodies, helping shape policies that affect the sector.
Promoting Education: CIBJO organizes events and conferences aimed at improving industry knowledge and providing training for jewellery professionals.
The CIBJO Blue Book Series

CIBJO publishes a series of Blue Books that provide detailed, standardized guidelines on the grading and description of various jewellery materials, such as diamonds, gemstones, pearls, and precious metals.
These Blue Books are recognized and respected in the industry, offering a globally accepted reference for the jewellery trade.
Sustainability and Corporate Social Responsibility (CSR)

CIBJO promotes sustainable sourcing and corporate social responsibility (CSR) in the jewellery industry, encouraging members to adopt ethical practices and ensure that materials such as diamonds and gemstones are sourced responsibly.
The organization also supports the Kimberley Process Certification Scheme, which aims to prevent the trade in conflict diamonds.
Annual Congress and Conferences

CIBJO hosts an annual congress, bringing together industry leaders, experts, and professionals to discuss challenges, opportunities, and developments in the global jewellery trade.
Importance of CIBJO in the Jewellery Industry
CIBJO is an essential body for ensuring the smooth functioning of the global jewellery market, promoting fair trade, sustainability, and ethical practices. It offers guidance on a wide range of industry issues, including gemstone sourcing, product quality standards, and the future of the jewellery sector.

DCLA (Diamond Certification Laboratory of Australia) is the official CIBJO laboratory for Australia, ensuring that diamond grading and certification standards in the country align with global best practices set by CIBJO. This partnership helps maintain accuracy, consistency, and ethics in the jewellery trade, promoting transparency in the Australian diamond market and ensuring high-quality standards are met.

Diamond clarity refers to the presence and visibility of inclusions (internal flaws) and blemishes (external flaws) within or on the surface of a diamond. The clarity of a diamond significantly affects its overall appearance, brilliance, and value.

Diamond Clarity Grading Scale
The Gemological Institute of America (GIA), one of the most respected grading authorities, uses a clarity scale to evaluate diamonds. The scale ranges from Flawless (FL) to Included (I3). The GIA clarity scale includes the following grades:

Flawless (FL)

No internal or external imperfections visible under 10x magnification.
The highest clarity grade and extremely rare.
Internally Flawless (IF)

No internal inclusions, but there may be minor surface blemishes visible under 10x magnification.
Very rare and highly valuable.
Very, Very Slightly Included (VVS1 and VVS2)

VVS1: Inclusions are extremely difficult to detect under 10x magnification.
VVS2: Inclusions are still very difficult to detect but may be visible to a skilled grader.
These diamonds have excellent clarity, and their inclusions are barely perceptible.
Very Slightly Included (VS1 and VS2)

VS1: Inclusions are difficult to detect under 10x magnification.
VS2: Inclusions are easier to see under magnification but still difficult for the untrained eye.
These diamonds are high quality and commonly found in fine jewellery.
Slightly Included (SI1 and SI2)

SI1: Inclusions are noticeable under 10x magnification, but not always visible to the naked eye.
SI2: Inclusions are visible under magnification and may be visible to the naked eye in some diamonds.
These diamonds are more affordable, but clarity is still relatively good.
Included (I1, I2, and I3)

I1: Inclusions are obvious under magnification and may be visible to the naked eye.
I2: Inclusions are easily visible and affect the diamond’s transparency and brilliance.
I3: Inclusions are highly visible and can affect the durability of the diamond.
Diamonds in this category are generally lower in value due to the impact of visible inclusions.
Factors Influencing Diamond Clarity
Size, Number, and Location of Inclusions: Larger or numerous inclusions generally lower the clarity grade. Inclusions near the centre of the diamond (table) are more impactful than those near the edges.
Type of Inclusions: Some inclusions, like feathers (small cracks) or carbon spots (small black dots), may be more noticeable than others.
Visibility: Whether inclusions are visible to the naked eye or only under magnification significantly affects the clarity grade.
Clarity and Diamond Value
Higher Clarity: Diamonds with higher clarity grades (like FL, IF, and VVS) tend to be rarer and more expensive.
Lower Clarity: Diamonds with lower clarity (such as SI and I grades) are more affordable, though they may have visible inclusions.
Clarity vs. Other Cs
While clarity is important, it is only one of the 4Cs that determine a diamond’s overall quality. Cut and colour are often more influential on a diamond’s brilliance and aesthetic appeal than clarity, especially when the inclusions are small or well-placed.

Clarity enhancement in diamonds refers to the process of improving the appearance of a diamond by reducing the visibility of inclusions and blemishes. This is often done to diamonds with lower clarity grades to increase their marketability and value. However, it is important to note that clarity-enhanced diamonds can be priced differently from untreated diamonds, and the enhancement methods can affect their long-term durability and appearance.

Common Clarity Enhancement Techniques:
Laser Drilling

This process is used to remove dark inclusions, such as black carbon spots or feathers (small cracks), by creating a small hole through the diamond to the inclusion.
A laser beam is used to vaporize the inclusion, making it less visible.
Pros: This method can significantly improve the diamond’s clarity by removing visible inclusions.
Cons: The laser drilling process can leave a small tunnel or cavity in the diamond, which may affect its structural integrity and can be visible under magnification.
Fracture Filling (Laser-Enhanced or HPHT)

This method involves filling cracks or fractures (feathers) with a special glass-like substance or a material that is similar in appearance to the diamond itself.
The filler improves the clarity of the diamond by making the inclusion less noticeable.
Pros: It can improve the diamond’s appearance by making cracks and fractures blend with the diamond, especially for diamonds with I clarity grades.
Cons: Fracture-filled diamonds can be more prone to damage, as the filler material can be less durable than the diamond itself. It is also detectable by trained gemologists under magnification.
High Pressure High Temperature (HPHT) Treatment

This method is mainly used on diamonds with a brown or yellowish tint, but it can also be applied to enhance clarity.
It involves subjecting the diamond to extremely high pressure and temperature conditions, which can cause some inclusions (especially graining or carbon spots) to be less noticeable.
Pros: It is an effective way to reduce the appearance of certain inclusions and may improve the overall colour and clarity of the diamond.
Cons: HPHT treatment can cause certain inclusions to become more prominent over time, and the process is not always fully reversible.
Implications of Clarity Enhancement:
Impact on Value:

Clarity-enhanced diamonds are generally priced lower than untreated diamonds of the same carat weight, cut, and colour.
The enhancement can improve the diamond’s marketability, but it is important for buyers to understand that the treatment affects the diamond’s long-term value.
Disclosure and Transparency:

Ethical practices in the diamond industry require disclosure of any clarity enhancements, as these treatments can affect the diamond’s value and durability.
Gemological laboratories such as GIA and DCLA will include information on any clarity enhancements in the diamond’s grading report. It’s important for buyers to request this information when purchasing a diamond.
Durability:

Depending on the type of enhancement, the durability of the diamond may be impacted. For example, a fracture-filled diamond may be more susceptible to damage because the filling material is not as hard as the diamond.
It is recommended to be cautious when cleaning or setting clarity-enhanced diamonds, as the treatments can weaken the stone.
Resale and Investment Considerations:

Clarity-enhanced diamonds may not retain their value as well as untreated diamonds in the secondary market. Their resale value can be lower because of the treatments applied.
Should You Consider Clarity Enhancement?
Clarity-enhanced diamonds can be an affordable option for those looking to get a larger or more visually appealing diamond without the higher price tag of an untreated high-clarity stone.
However, it’s essential to weigh the potential downsides, including the risk of damage and reduced long-term value.

Cleavage in a diamond refers to the ability of a diamond to split or fracture along specific planes due to its crystalline structure. These planes of weakness occur naturally within the diamond’s crystal lattice, and if struck in the right way, the diamond may break or cleave along these lines. Cleavage is one of the most important characteristics of a diamond’s durability and is often associated with its vulnerability to damage.

Key Facts About Cleavage in Diamonds:
What Is Cleavage?

Cleavage refers to the breaking or splitting of a diamond along natural planes of weakness. These planes correspond to the directions in the diamond’s crystal structure where the bonds between atoms are weaker.
Diamond crystals have four cleavage planes, but these are rarely all present in a single diamond. The most common cleavage occurs along one or two of these planes.
Cleavage vs. Fracture:

Cleavage is a clean, smooth break that happens along the natural crystal planes, and it often occurs when a diamond is subjected to a sharp blow.
In contrast, a fracture (or crack) is a less predictable break, which can happen anywhere in the diamond and is generally irregular rather than smooth.
Vulnerability to Cleavage:

Because of its hardness (the hardest naturally occurring material), diamonds are not prone to breaking under normal conditions, but they can be shattered if hit with a strong impact in the right direction.
Sharp impacts or blows to a diamond, especially along its cleavage planes, can cause cleavage to occur, resulting in a clean break that might be irreparable.
Impact on the Diamond’s Value:

A diamond with cleavage is considered more fragile and less valuable than a diamond without cleavage, especially if the cleavage is visible or affects the diamond’s appearance.
Diamonds that are cut too thin or with sharp corners (such as certain fancy shapes like the princess cut) are more likely to develop cleavage fractures because they have less structural strength at those points.
Inclusions and natural fractures can sometimes affect the cleavage of a diamond, especially if the inclusions are near the cleavage planes.
Preventing Cleavage:

Careful Handling: Diamonds should be handled gently and not subjected to heavy blows or sharp impacts.
Setting: The setting plays a significant role in protecting the diamond from cleavage. A setting that covers or shields the diamond’s vulnerable edges, such as a bezel setting, can help prevent accidental damage.
Cleaning: Use gentle methods for cleaning diamonds. Ultrasonic cleaners or steam cleaners can sometimes cause stress to the diamond, leading to cleavage if the diamond is already weakened by a flaw.
Signs of Cleavage:

If a diamond has been damaged by cleavage, you may notice sharp, clean breaks at specific points along the diamond’s surface. These breaks are usually smooth and can sometimes be seen with magnification.
How to Avoid Cleavage-Related Damage:
When buying a diamond, especially a fancy-shaped diamond, it’s essential to ensure that the diamond is cut well to avoid thin or sharp points, which could make it more susceptible to cleavage.
Professional diamond setting and proper care and handling are critical to preventing damage to your diamond from impact.
Repairing Cleavage Damage:
If a diamond suffers cleavage, it cannot typically be repaired to its original state. However, re-cutting the diamond may be an option in some cases, though this could result in a reduction of carat weight.
In some cases, the diamond may be set in such a way that the cleavage is not visible, such as by using protective settings or prongs to shield the affected area.

A diamond with a relatively small table refers to a diamond where the table facet (the large, flat surface at the top of the diamond) is smaller in proportion to the overall size of the diamond than what is typically seen in other diamonds.

Understanding the Table in a Diamond
The table is the topmost, flat facet of the diamond, and it is usually circular in shape. It’s the largest facet and is positioned at the top of the stone.
The size of the table, along with the crown (the upper part of the diamond), plays a significant role in determining the diamond’s brilliance (how much light it reflects and how it sparkles).
Characteristics of a Diamond with a Small Table
Proportion of the Table

A diamond with a small table typically has a lower table-to-diameter ratio. In other words, the diameter of the table is smaller than in diamonds with more standard proportions.
This means that the facets surrounding the table are larger, which can affect how light enters and exits the diamond, influencing its sparkle.
Aesthetic Impact

A smaller table may result in a more subtle brilliance or a different light performance compared to diamonds with larger tables. It may create more interesting fire (the dispersion of light into colours) but at the cost of some overall brightness.
Cut Quality: The shape and proportions of the diamond are crucial to its overall appearance. A diamond with a small table may look slightly deeper, which could affect the way it sits in the setting and how light reflects from its surface.
Types of Diamonds with Small Tables

Diamonds like the princess cut or old European cut can sometimes feature smaller tables, especially if they are cut with more traditional proportions.
The round brilliant cut typically has a larger table compared to other cuts, so a small table in this cut might indicate a more unique or less conventional style.
Light Performance

In a diamond with a smaller table, light performance can be influenced by the diamond’s cut angles, depth, and crown. The smaller table may reflect light differently, potentially making the diamond seem less brilliant but with more internal sparkle or fire due to the increased number of larger facets.
Impact on Diamond’s Value

The cut and proportions of a diamond are crucial to its value. A smaller table might affect the overall appearance of the diamond, making it seem less brilliant, especially if it compromises the symmetry or light performance of the stone.
A diamond with a smaller table might be considered less desirable if it leads to undesirable proportions, as this could reduce its overall market appeal compared to diamonds with standard table sizes.
Choosing a Diamond with a Small Table:
If you’re considering a diamond with a relatively small table, make sure to focus on other important factors like the cut quality, symmetry, and light performance.
A well-cut diamond with a smaller table can still be beautiful, but it’s important to understand how the proportions affect the overall look of the stone.
Always check the diamond’s grading report from reputable labs like GIA or DCLA to ensure the proportions are in line with your aesthetic preferences and expectations.

A cloud in a diamond refers to a type of inclusion consisting of tiny, hazy clusters of fine, needle-like inclusions that appear as a clouded or milky area within the diamond. These inclusions are typically very small and difficult to see without magnification. A cloud can sometimes be composed of tiny crystals of carbon or other microscopic inclusions within the diamond.

Characteristics of Clouds in Diamonds
Appearance

A cloud in a diamond appears as a cloudy, hazy, or milky area within the stone. It is not a single inclusion but rather a group of inclusions that blend together, giving the effect of a cloud.
Clouds are typically microscopic in size, so they are often not visible to the naked eye, especially if they are near the centre of the diamond. However, they can affect the overall clarity and brilliance of the diamond.
Location of Clouds

Clouds can appear anywhere in the diamond, but they are typically found in the interior (internal inclusions) rather than on the surface.
If a cloud is near the surface of the diamond, it may be visible to the naked eye, affecting the diamond’s overall appearance.
Impact on Clarity

The presence of a cloud affects the diamond’s clarity grade, but whether it has a significant impact on its appearance depends on its size, location, and visibility.
If a cloud is large or located near the centre of the diamond, it may reduce the diamond’s brilliance and sparkle by obstructing light and causing the diamond to look cloudy or less transparent.
Small clouds that are not visible without magnification typically have little to no effect on the diamond’s overall appearance, and they may not significantly lower the clarity grade.
Clouds and Light Performance

Clouds can sometimes affect how light travels through the diamond, leading to a slight reduction in brilliance. However, in many cases, their effect on light performance is minimal, especially if the cloud is small or located in an inconspicuous part of the diamond.
Larger clouds may scatter light, causing the diamond to lose some of its fire (the dispersion of light into rainbow colours) and brilliance (the overall brightness or sparkle).
Grading Cloud Inclusions

Cloud inclusions are often considered when determining a diamond’s clarity grade. They typically fall under the “SI” (Slightly Included) or “I” (Included) categories depending on their size and visibility.
Diamonds with small, inconspicuous clouds may still receive high clarity grades like VS (Very Slightly Included) or VVS (Very, Very Slightly Included) if the cloud does not significantly affect the overall appearance of the stone.
Cloud vs. Other Inclusions
Feathers: Unlike clouds, which are made of multiple tiny inclusions, feathers are single inclusions that resemble cracks or fractures in the diamond. Feathers may be more easily seen or cause damage if they are near the surface.
Pinpoints: A pinpoint is a single, tiny inclusion, often a carbon crystal, and is generally much smaller than the inclusions found in a cloud.
Clouds and Diamond Value
The presence of a cloud can lower a diamond’s clarity grade, especially if it affects the stone’s appearance and brilliance. However, if the cloud is small and not visible to the naked eye, the impact on value may be minimal.
Diamonds with higher clarity grades, such as IF (Internally Flawless) or VVS, are typically priced higher than diamonds with visible inclusions like clouds.
Is a Cloud Bad for a Diamond?
A cloud doesn’t necessarily mean the diamond is “bad.” Many diamonds have small clouds that don’t affect their visual appeal. The key is whether the cloud is visible to the naked eye and if it reduces the diamond’s overall sparkle and brilliance.
High-quality diamonds with small or well-positioned clouds can still be stunning and maintain their value. The presence of a cloud is just one factor in a diamond’s overall quality assessment.

A coated diamond refers to a diamond that has undergone a treatment where a thin layer of material is applied to the surface of the diamond to alter its colour, appearance, or shine. Coating can be used for aesthetic purposes or to improve certain aspects of the diamond, such as its resistance to scratches or its overall visual effect.

Common Types of Coatings Used on Diamonds
Colour Coating (Tinting)

Purpose: To alter the diamond’s colour, making it appear more vibrant or to give it a specific hue, such as blue, yellow, or pink.
How It’s Done: The diamond is coated with a thin layer of coloured material, often a chemical coating that reacts with the surface of the diamond.
Appearance: This can create a dramatic shift in the diamond’s overall look. However, the coating may wear off over time, especially if the diamond is exposed to wear or cleaning.
Temporary: Coated diamonds may lose their colour enhancement over time as the coating wears down.
Protective Coating

Purpose: To add a layer of protection to the diamond’s surface, preventing scratches, blemishes, and other damage.
How It’s Done: A thin, transparent layer is applied to the surface of the diamond. This can provide a protective shield that makes the diamond more resistant to daily wear and tear.
Durability: While protective coatings can help preserve the appearance of a diamond, they can wear off over time and may need to be reapplied.
Anti-Reflective Coating

Purpose: To reduce the reflection of light from the diamond’s surface and enhance its brilliance.
How It’s Done: A thin layer of material is applied to the surface of the diamond to prevent light from reflecting off the surface, which can enhance the visual appeal by making the diamond appear more sparkly and brilliant.
Effect: This is especially useful for diamonds with low-quality cuts or those that don’t display their full brilliance.
Black Coating

Purpose: To create a black diamond effect or to enhance the contrast between the diamond and its setting.
How It’s Done: A black coating is applied to the surface, giving the diamond a deep, opaque black appearance.
Appearance: This effect is mainly used in fashion jewellery or when creating novelty diamonds, not for traditional diamond engagement rings.
Permanence: The coating can wear off, especially in diamonds exposed to frequent handling or cleaning.
Considerations When Purchasing a Coated Diamond
Durability of the Coating

Many diamond coatings, especially those for colour enhancement, can wear off over time due to exposure to heat, chemicals, or physical wear. This makes coated diamonds less permanent in appearance than untreated diamonds.
Protective coatings can help preserve the diamond’s surface, but like other coatings, they will deteriorate over time and may require re-coating.
Value and Transparency

Coating treatments can decrease the value of a diamond, especially if the coating is used to alter the colour of a lower-quality diamond. Coating treatments are typically disclosed in diamond grading reports, so it’s important to verify the treatment when purchasing a coated diamond.
Coatings are usually not permanent, and their effect on the diamond’s long-term value can be unpredictable.
Ethical Considerations

Some consumers prefer natural, unaltered diamonds for their authenticity and value, while others may be drawn to coated diamonds for their unique appearance at a lower price point.
Be sure to inquire about the coating’s material, longevity, and whether it affects the diamond’s natural characteristics.
Impact on Resale

Diamonds that have been coated for cosmetic reasons, especially for colour, may have a lower resale value compared to untreated diamonds because of the potential wear of the coating over time.
If you’re purchasing a coated diamond as an investment, it’s important to consider that coatings might diminish the stone’s future market value.

A Cognac diamond is a type of brown diamond that is characterized by its rich, warm brown hues with shades ranging from light yellow-brown to deep, intense reddish-brown. The name “Cognac” is derived from the rich, amber-like colour of the famous Cognac liquor, and it is used to describe diamonds that display a similar amber or reddish-brown colour.

Key Characteristics of Cognac Diamonds:
Colour Range:

Cognac diamonds can range from light brown to dark reddish-brown, with some stones exhibiting an almost amber or chocolate brown appearance. The deeper the colour, the more intense the cognac hue, which is what gives the diamond its signature name.
Overtones of yellow or red may also be present in higher-quality Cognac diamonds, giving them a more vivid and unique visual appeal.
Formation:

Cognac diamonds are formed in the same way as other diamonds, but their distinctive colour is caused by natural radiation during their formation process. The presence of certain elements, such as nitrogen, is responsible for the brown colour, which can vary in intensity depending on the diamond’s unique composition and the conditions under which it formed.
Diamond Grading and Colour:

Colour grading for Cognac diamonds follows the same system used for all diamonds, with diamonds being graded on a scale from D (colourless) to Z (light yellow or brown). Cognac diamonds typically fall in the range of K to Z on the colour scale.
While the grading system for diamonds typically focuses on the absence of colour (with more valuable diamonds being colourless), Cognac diamonds have their own unique appeal and are valued for their warm, rich colours rather than for being colourless or near-colourless.
Rarity and Value:

While brown diamonds are relatively common in nature, Cognac diamonds are rarer than other types of brown diamonds because of their deep, rich hue. High-quality Cognac diamonds with vibrant, intense colours are considered more valuable.
The value of a Cognac diamond is determined by its colour (depth and richness), clarity, and cut, just like any other diamond. However, the unique colour can make the Cognac diamond stand out and appeal to those looking for a more distinctive and fashionable stone.
Appearance and Appeal:

The warm brown tones of a Cognac diamond give it a distinctive, luxurious appearance that pairs well with various metal settings like rose gold, yellow gold, or platinum. The warm tones can make it an attractive choice for engagement rings, necklaces, and other fine jewellery pieces.
Cognac diamonds often have a vintage or antique aesthetic, making them popular for those seeking a more unique or unconventional look, as opposed to the traditional clear diamond.
Common Treatments:

Some brown diamonds, including Cognac diamonds, are treated to enhance their colour. HPHT (High Pressure High Temperature) treatment is one such method used to improve the colour and clarity of brown diamonds. However, Cognac diamonds with natural, untreated colour are considered more desirable and valuable.
Unlike other coloured diamonds (such as pink or blue diamonds), the natural brown colour of Cognac diamonds is typically well-regarded, and the treatment is not always necessary to enhance their beauty.
Why Choose a Cognac Diamond?
Unique Beauty: The warm, earthy tones of Cognac diamonds offer a unique alternative to traditional colourless diamonds. They stand out for their rich, luxurious look, which can be especially appealing for those looking for something distinctive.
Versatility in Design: Cognac diamonds pair beautifully with a variety of metals, particularly rose gold or yellow gold, which complement the diamond’s warm tones. They can be used in both modern and vintage-inspired jewellery designs.
Rarity: High-quality Cognac diamonds, especially those with deep, intense colour, are relatively rare and can be a special choice for engagement rings, anniversary rings, or other fine jewellery pieces.
Value: While the price of Cognac diamonds can vary depending on the size, quality, and colour saturation, they are generally more affordable than colourless diamonds of the same size and quality.
Cognac Diamond vs. Other Brown Diamonds
While brown diamonds are commonly referred to by a variety of names (such as chocolate, champagne, and cognac), Cognac diamonds are considered to be among the highest quality brown diamonds due to their rich, deep colour. Other brown diamonds, like champagne diamonds, tend to have lighter, more yellowish-brown hues, while Cognac diamonds typically feature a richer reddish-brown tone.

A diamond cold laser inscription is a process where a laser is used to etch a unique identifier, such as a serial number, logo, or personalized message, onto the girdle (the outer edge) of a diamond. This inscription is typically microscopic and can be used to verify the diamond’s authenticity, its grading report, or other key information.

Key Features of Cold Laser Inscription:
Laser Technology:

The cold laser used in the process is a low-energy laser that does not generate enough heat to affect the diamond’s structure or its inherent properties.
Unlike traditional laser etching methods that can produce heat or cause microfractures, cold lasers use a precise, controlled beam to mark the diamond without damaging it.
Precision:

Cold lasers are capable of engraving extremely fine details that are invisible to the naked eye but can be magnified with a loupe or microscope.
The engraved text or design is typically small, with high precision, often ranging from 1 to 2 millimetres in length.
Purpose:

The primary purpose of cold laser inscriptions is to provide a form of identification that links a diamond to its grading report or to prove its authenticity. This can help to confirm the diamond’s origin, its quality grade, and its specific characteristics as detailed in the accompanying grading document.
It is also used by jewellers to add personalized messages, such as initials, dates, or sentimental inscriptions, making the diamond more meaningful to the buyer.
Common Types of Inscriptions:

GIA (Gemological Institute of America) Serial Number: Many diamonds graded by the GIA are inscribed with their unique serial number that corresponds to the report issued by the institute.
Personal Messages: Some buyers opt for personalized engravings, such as initials, special dates, or short phrases.
Brand Logos: Some jewellery brands may include their logo or trademark on the diamond for brand identification.
Certification Details: Other information, such as the diamond’s cut, colour, and clarity, may also be inscribed to help identify and verify the diamond’s grading.
Location of Inscription:

The girdle of the diamond is the most common location for cold laser inscriptions because it’s the outer edge of the diamond, making it easy to access without damaging the table or other more delicate areas.
The inscription is typically placed in an area that is not visible when the diamond is set in jewellery.
Advantages of Cold Laser Inscription:

No Damage to Diamond: Since the cold laser process uses minimal heat, it does not affect the diamond’s structural integrity or cause any physical damage to the stone.
Permanent and Invisible: The engraving is permanent and does not wear off. It is also invisible to the naked eye, meaning it won’t affect the aesthetic appeal of the diamond.
Adds Value: An inscription can add a layer of authenticity and security, ensuring the diamond can be identified and traced back to its grading report.
Customization: Cold laser inscriptions allow for personalized engravings, making the diamond a unique and meaningful piece of jewellery for the buyer.
Visibility and Inspection:

Microscopic Inspection: While the engraving is usually invisible to the naked eye, it can be easily seen under magnification using a loupe or a microscope.
Some diamond grading labs, like the GIA, will include the serial number or specific laser inscription details in their reports, which can be used to identify the diamond by its unique marking.
Considerations When Using Cold Laser Inscriptions:
Impact on Resale Value: Generally, cold laser inscriptions do not affect the resale value of a diamond, but they provide added security for the owner, as the diamond can be traced back to its certificate. However, if the inscription is highly personalized or specific, it may limit the market for resale.
Verification: If you are buying a diamond with a laser inscription, make sure that the inscription matches the details listed in the certification or grading report. Reputable diamond grading laboratories often verify the inscriptions, and a matching number helps to confirm authenticity.
Customization Limits: Cold laser inscriptions are limited in size, and large, complex designs or messages might not fit in the small area available on the girdle. However, simple messages, dates, or identifiers are commonly used.
Cold Laser vs. Traditional Laser Inscription:
Cold Laser: Low-energy, does not affect the diamond’s structural integrity, and is used for fine, precise engravings.
Traditional Laser: Higher energy, may cause heat damage, and is used for deeper engravings or larger designs.
How to Check for a Cold Laser Inscription:
To check for a cold laser inscription, you can examine the girdle of the diamond under a loupe or microscope. It will appear as tiny, precise text.
Alternatively, if you have the diamond’s certification or grading report from a lab like GIA, you can cross-reference the inscription with the report to ensure it matches the unique identifier of the diamond.

Diamond Colour is one of the most important factors in determining a diamond’s quality and value. It refers to the absence of colour in a diamond, with diamonds being graded on a scale that ranges from colourless to light yellow or brown. The more colourless a diamond is, the higher its value.

Diamond Colour Grading:
The most common diamond colour grading scale is the GIA (Gemological Institute of America) scale, which is used by most gemological labs, including the DCLA (Diamond Certification Laboratory of Australia).

On the GIA scale, diamonds are graded from D to Z, with D being colourless and Z being diamonds with noticeable colour.

D – F (Colourless to Near Colourless):

D: Completely colourless, the highest grade. These diamonds are rare and extremely valuable.
E and F: Near colourless, with only slight traces of colour detectable under magnification. These diamonds still appear colourless to the naked eye and are highly valued.
G – J (Near Colourless):

These diamonds are still near colourless and typically look white to the naked eye. However, when compared to diamonds in the D-F range, there may be a very subtle hint of colour.
G: Near colourless, slightly less valuable than F but still excellent in appearance.
H: Slightly tinted, but appears mostly white to the naked eye.
I and J: Noticeably tinted, but still often appear white in settings that complement the diamond’s colour.
K – M (Faint Yellow or Brown):

Diamonds in this range show faint yellow or brown tint, which becomes more noticeable as the grade progresses.
N – Z (Light Yellow or Brown):

These diamonds show a more noticeable colour (yellow or brown), and while still diamonds, they are typically considered less valuable than those in the D-J range.
DCLA and the Diamond Colour Grading Process:
The DCLA (Diamond Certification Laboratory of Australia) is one of the leading gemological laboratories in Australia that provides reliable and accurate diamond certification, including diamond colour grading. DCLA follows internationally recognized standards for grading diamond colour, similar to the GIA scale.

As part of their grading process, DCLA uses an official master set of diamonds to compare the diamond in question and determine its exact colour grade. This ensures that the grading is precise and consistent with global standards. The DCLA master set is made up of a range of diamonds, each representing one of the standard colour grades, and serves as a reference tool for accurate grading.

DCLA’s Official Master Set for Colour Grading:
The DCLA master set consists of diamonds of known colour that act as the benchmark for evaluating the colour of other diamonds.
These reference diamonds are carefully selected to represent each colour grade, from D (colourless) to Z (light yellow or brown). When a diamond is submitted for certification, DCLA compares it to this master set to determine its accurate colour grade.
DCLA’s commitment to precision ensures that their colour grading is consistent, and their grading system is recognized by jewelers, consumers, and industry professionals.
Importance of Colour in Diamond Valuation:
Colourless diamonds (D-F grades) are the rarest and typically the most expensive because they allow for the most reflection of light and therefore exhibit the most brilliance and fire.
Near colourless diamonds (G-J grades) offer excellent value for those looking for a balance of quality and price. They are often indistinguishable from the higher grades without close inspection.
Diamonds with faint to noticeable yellow or brown tints (K-Z grades) tend to be more affordable but may lack the brilliance of the higher grades due to the presence of colour.
Why Choose a Diamond with a DCLA Certification?
Transparency and Trust: DCLA provides accurate, reliable colour grading based on internationally accepted standards, which ensures that the buyer knows exactly what they are purchasing.
Consistency: The DCLA Master Set ensures that diamonds are evaluated based on consistent criteria, allowing for a reliable comparison of diamonds and ensuring that the colour grading is trustworthy.
Security: Diamonds certified by DCLA are marked with a unique laser inscription that helps identify and authenticate the diamond, adding another layer of security for buyers.
How to Choose the Right Diamond Colour:
If brilliance is your top priority, opt for a D-F grade diamond.
If you are looking for a better value without sacrificing much on appearance, G-H grade diamonds are a great choice.
For larger diamonds or those in settings where the diamond is not viewed up close, I-J diamonds can offer good value for a larger size.

A coloured diamond is a diamond that exhibits a hue other than the traditional colourless range. While most diamonds appear colourless or near-colourless, coloured diamonds come in a variety of shades, ranging from yellow, brown, and blue to rare colours like pink, green, and red. The colour in these diamonds is caused by elements or chemical processes during their formation, which result in various hues and saturations.

Key Types of Coloured Diamonds:
Yellow Diamonds:

Yellow diamonds are among the most common coloured diamonds and owe their hue to the presence of nitrogen atoms in the crystal lattice. The nitrogen atoms absorb blue light, resulting in the yellow colour.
These diamonds can range from light yellow to vibrant canary yellow.
Intensity and Saturation: The more intense the yellow colour, the more valuable the diamond. The colour is graded on a scale from light yellow to fancy vivid yellow.
Brown Diamonds:

Brown diamonds are also relatively common and are often referred to as chocolate diamonds or cognac diamonds based on their specific hue. The colour in brown diamonds is typically caused by plastic deformation during their formation, which results in the diamond absorbing blue light.
Brown diamonds can be found in various shades, including light brown, champagne, and rich cognac.
They are graded based on the depth of colour, with higher intensities like fancy intense brown being more valuable.
Blue Diamonds:

The striking blue colour of these diamonds is caused by the presence of boron atoms in the crystal lattice. Boron absorbs yellow and red light, leaving behind the blue hue.
Blue diamonds can range from light blue to vivid blue. The most famous blue diamond is the Hope Diamond, which is a deep blue.
The colour intensity plays a significant role in the value, with the more intense the blue, the more valuable the diamond.
Pink Diamonds:

Pink diamonds are some of the rarest and most sought-after coloured diamonds in the world. Their colour is thought to be the result of structural defects in the diamond’s crystal lattice, which causes the absorption of certain wavelengths of light.
The colour can range from light pink to vivid pink, with fancy intense pink diamonds being the most valuable.
Pink diamonds are primarily found in Australia’s Argyle mine, though the mine has since been closed, making these diamonds even rarer.
Green Diamonds:

Green diamonds derive their colour from the presence of natural radiation that causes the diamond to absorb certain wavelengths of light, leaving a greenish hue.
The green can range from light green to deep, vivid green. Natural green diamonds are quite rare and can be valuable depending on the intensity of the colour.
Treated green diamonds are also available, where the green hue is enhanced through a process known as irradiation.
Red Diamonds:

Red diamonds are among the rarest of all coloured diamonds, and their colour is often attributed to defects in the diamond’s crystal structure. The exact cause of the red colour is not fully understood, but it is believed to result from a particular defect that causes the diamond to absorb blue and yellow light.
The red diamond can range from light red to deep red, with the most famous example being the Moussaieff Red Diamond.
Due to their extreme rarity, red diamonds command extremely high prices.
Orange Diamonds:

Orange diamonds are rare and owe their colour to the presence of nitrogen atoms, similar to yellow diamonds. However, the arrangement of these nitrogen atoms results in a different colour spectrum.
These diamonds can range from light orange to deep fiery orange. The more intense the colour, the more valuable the diamond.
Purple Diamonds:

Purple diamonds are extremely rare and are often caused by a combination of structural defects and the presence of hydrogen during the diamond’s formation.
These diamonds typically show a mix of red and blue hues, which gives them a unique, vibrant appearance.
Colour Grading of Coloured Diamonds:
The grading system for coloured diamonds differs from that of colourless diamonds. Coloured diamonds are graded based on two main factors:

Hue: The colour of the diamond, such as yellow, blue, or pink.
Tone: The lightness or darkness of the colour (from light to dark).
Saturation: The intensity of the colour (from faint to vivid or intense).
Diamonds with more intense and saturated colours, especially those classified as fancy vivid, are typically the most valuable. Coloured diamonds are graded with terms like fancy light, fancy, fancy intense, and fancy vivid, where the more vivid the colour, the more valuable the diamond.

Factors Affecting the Value of Coloured Diamonds:
Rarity: The rarity of the colour is a major factor in determining the value of a coloured diamond. For example, red diamonds and blue diamonds are significantly rarer than yellow diamonds, making them more valuable.
Colour Intensity: The intensity of the colour (saturation and tone) greatly influences the price. Diamonds with vivid, deep hues command higher prices than those with lighter or less saturated colours.
Size: Coloured diamonds, like colourless diamonds, are valued by their carat weight. Larger coloured diamonds with strong, vivid colours are extremely rare and fetch exceptionally high prices.
Origin: Some coloured diamonds, like pink diamonds from the Argyle mine, are particularly valuable because of their rarity and the mine’s closure, making the diamonds even more scarce.
Treatments of Coloured Diamonds:
Some coloured diamonds undergo enhancement treatments to improve their colour. For example:

High Pressure High Temperature (HPHT) and irradiation are methods used to enhance the colour of diamonds, especially for those in the yellow, brown, and green ranges.
Natural coloured diamonds are often preferred for their uniqueness and value, as treated diamonds generally have a lower resale value.
The DCLA and Coloured Diamonds:
The DCLA (Diamond Certification Laboratory of Australia) offers colour grading for coloured diamonds using the standard grading scale and methodology, ensuring consistency with international grading systems. DCLA’s certification of coloured diamonds will include detailed colour information, including the hue, tone, and saturation of the diamond, providing buyers with a comprehensive understanding of the diamond’s quality and characteristics.

Conflict diamonds, also known as blood diamonds, are diamonds that are mined in war zones or regions controlled by rebel forces who use the profits to fund armed conflict against legitimate governments. The trade of these diamonds often contributes to human rights abuses, including forced labour, child labour, and violence.

The Origins of Conflict Diamonds:
Conflict diamonds gained global attention during the 1990s, particularly due to the civil wars in countries such as Sierra Leone, Liberia, Angola, and Democratic Republic of the Congo. Rebel groups in these regions often seized control of diamond-rich areas, using the diamonds to fund their military efforts, while civilians were subjected to horrific abuse.

The 1998 United Nations report on the diamond trade highlighted the issue of conflict diamonds, leading to increased awareness and international efforts to combat the trade.

The Kimberley Process Certification Scheme (KPCS):
In response to the growing concerns about conflict diamonds, the Kimberley Process Certification Scheme (KPCS) was established in 2003. The Kimberley Process is an international initiative aimed at preventing the trade in conflict diamonds. It sets requirements for member countries to certify that diamonds exported from their country are conflict-free.

Under the Kimberley Process, participating countries must:

Certify that diamonds have been mined and exported without contributing to armed conflict.
Ensure that diamonds are accompanied by a certificate stating their conflict-free origin.
Monitor and regulate the diamond trade within their borders, with customs authorities and diamond industries playing a key role in ensuring compliance.
While the Kimberley Process has made significant strides in reducing the trade in conflict diamonds, it has faced criticism and challenges, such as:

Loopholes in enforcement, allowing diamonds from conflict zones to enter the market through smuggling or fraudulent certification.
Limited scope: The Kimberley Process primarily addresses rough diamonds but does not extend to diamonds that are cut and polished, which can still end up on the market despite having been mined in conflict zones.
Impact on the Diamond Industry:
The diamond industry has taken steps to address the issue of conflict diamonds, and many major jewellers have pledged to only source diamonds that comply with the Kimberley Process certification. However, there is ongoing pressure on the industry to do more to ensure that diamonds are ethically sourced and to prevent the trade of diamonds that could fund violence or abuse.

The term “blood diamond” has also sparked public awareness, leading some consumers to demand greater transparency about the origins of their diamonds and prompting the rise of ethical and fair trade diamonds.

Alternatives to Conflict Diamonds:
Ethically Sourced Diamonds:

Many jewelers now offer ethically sourced diamonds, which are sourced from regions with strong human rights protections and strict environmental standards.
Some companies even go beyond the Kimberley Process, supporting fair trade initiatives and other certification programs that ensure diamonds are mined and traded responsibly.
Lab-Grown Diamonds:

Another alternative to conflict diamonds is the growing market for lab-grown diamonds. These diamonds are created in controlled environments using technology that mimics the natural diamond-forming process. Lab-grown diamonds are not only free from the ethical concerns of conflict diamonds but also often more affordable.
Traceable Diamonds:

Advances in technology have allowed for better tracking of diamonds from the mine to the retail store. Some diamonds now come with full traceability to verify that they were sourced responsibly and without contributing to conflict.
Consumer Responsibility:
As a consumer, it’s important to be aware of the ethical issues surrounding diamond purchasing. Asking questions about the origins of a diamond, requesting certification, and opting for brands that support ethical practices can all help reduce the demand for conflict diamonds.

Many consumers today are choosing diamonds that are conflict-free and come with traceable certifications to ensure they have not contributed to any form of violence or human rights abuse. Supporting ethical brands and lab-grown diamonds can also help ensure that the diamond industry works toward greater accountability.

The Role of DCLA:
The DCLA (Diamond Certification Laboratory of Australia) is committed to ensuring that the diamonds it certifies are conflict-free and adhere to internationally recognized standards. Through the Kimberley Process Certification Scheme, DCLA helps ensure that diamonds sourced and sold in Australia meet the highest ethical and legal standards. When purchasing diamonds, DCLA certification provides a level of assurance that the diamonds being bought have been sourced responsibly.

A diamond crown refers to a piece of jewelry, often a tiara or headpiece, that is adorned with diamonds and designed to be worn on the head. It is typically associated with royalty, formal occasions, or beauty pageants. Diamond crowns can vary greatly in style, size, and design, but they generally feature diamonds as the central embellishment, showcasing their sparkle and brilliance.

Types of Diamond Crowns:
Royal Crowns:

Historically, royal crowns have been a symbol of power, authority, and sovereignty. These crowns, worn by kings, queens, and emperors, were often studded with large, valuable diamonds and other precious gemstones.
Crown jewels of various nations often feature diamonds, with some crowns containing famous diamonds, such as the Koh-i-Noor or the Cullinan Diamond.
Tiara Crowns:

Tiaras are a type of diamond crown that are typically worn at weddings, state functions, or formal events. They are less imposing than royal crowns but still offer a striking, elegant look. Tiaras may feature a combination of diamonds and other gemstones, arranged in intricate designs.
Popular among beauty pageants and high-society events, tiaras are often seen worn by those of aristocratic or royal lineage.
Wedding Crowns:

Some brides opt for a diamond crown or tiara as part of their wedding ensemble, adding a touch of glamour and sparkle. Wedding crowns are often designed to complement the bridal gown and can be customized to suit the bride’s personal style.
These crowns are typically more delicate and feminine, with diamonds arranged in a more subtle manner compared to royal crowns.
Decorative or Fashion Crowns:

Fashion crowns or decorative crowns are designed for ceremonial or decorative purposes and may be worn at costume events or themed parties. These crowns can be more creative, featuring diamonds alongside other elements like pearls, colored gemstones, and intricate metalwork.
Famous Diamond Crowns:
The Imperial State Crown (UK): Worn by the monarch during the State Opening of Parliament, this crown is encrusted with diamonds, including the Cullinan II Diamond, one of the largest cut diamonds in the world.

The Russian Imperial Crown: This historic crown is known for its diamonds, emeralds, and other gemstones. It was part of the Russian Crown Jewels and was worn by the czars during coronation ceremonies.

**The Koh-i-Noor Diamond Crown: This crown features the Koh-i-Noor diamond, which has a long and controversial history, and was once part of the British crown jewels.

Diamond Crown Design Elements:
Shape and Style: Diamond crowns may have different shapes, such as round, oval, or arched designs. Some are designed with a single row of diamonds, while others may have multiple tiers or intricate patterns.

Diamonds in Settings: Diamonds in a crown can be set in various ways, including prong settings, bezel settings, or pave settings. The setting influences how much light the diamonds reflect, contributing to their overall sparkle.

Other Gemstones: While diamonds are the focal point of most crowns, other gemstones such as emeralds, rubies, sapphires, and pearls are often incorporated for additional color and visual interest.

Symbolism of Diamond Crowns:
Royalty and Power: Diamond crowns symbolize power, wealth, and prestige. Historically, crowns were worn by those who held political or royal authority, and their adornment with diamonds signified both their wealth and divine right to rule.

Elegance and Celebration: In modern times, diamond crowns (often tiaras) symbolize elegance and beauty, and they are often worn at significant life events like weddings, pageants, and milestone celebrations.

Endurance and Purity: Diamonds are also symbolic of eternity and purity, which is why they are often used in crowns for weddings, representing the longevity and enduring nature of love.

Caring for a Diamond Crown:
Because of their value and intricate design, diamond crowns require careful maintenance:

Regular Cleaning: Like any piece of diamond jewelry, a diamond crown should be cleaned regularly to maintain its sparkle. A gentle solution of water and mild dish soap with a soft brush can be used.
Storage: Crowns should be stored carefully in a soft cloth or padded box to prevent scratching. If the crown is worn frequently, regular checks by a jeweler to ensure that the diamonds are secure are recommended.

The term “diamond crown angle” typically refers to the angle at which the crown of a diamond (the upper portion above the girdle) is cut. This is an important aspect of a diamond’s cut quality, as it influences the diamond’s brilliance and sparkle.

Key Points about the Diamond Crown Angle:
Crown:

The crown of a diamond is the top part of the diamond, extending from the girdle (the widest part of the diamond) to the table (the flat top surface).
The crown angle, or crown facet angle, is the angle formed between the plane of the table and the crown facets (the facets that make up the crown).
Crown Angle and Brilliance:

The crown angle plays a crucial role in how well a diamond reflects light. The angle affects how light enters and exits the diamond, impacting its brilliance (the white light reflected from the diamond) and fire (the dispersion of light into different colours).
A well-proportioned crown angle helps the diamond reflect light optimally, creating maximum brilliance and sparkle.
If the angle is too steep, the diamond can appear dark and lack brilliance, as light is directed away from the stone. Conversely, if the angle is too shallow, the diamond may lack depth and the light can escape through the bottom.
Ideal Crown Angle:

For a round brilliant diamond, the ideal crown angle typically ranges from 34° to 35°. Diamonds within this range tend to exhibit optimal brilliance and fire.
However, the crown angle must be considered in combination with other factors like the pavilion angle (the angle of the lower portion of the diamond) to achieve ideal proportions and light performance.
Ideal proportions typically result in a diamond that performs well in terms of both brilliance and fire, creating a visually pleasing sparkle.
Diamonds with Different Crown Angles:

Steep Crown Angle: A crown angle greater than 35° can lead to a steep crown, which might cause the diamond to appear darker or less sparkly due to light leakage.
Shallow Crown Angle: A crown angle lower than 34° can result in a shallow crown, which can make the diamond appear flat and may cause light to escape out of the sides of the stone, diminishing its brilliance.
Measuring the Crown Angle:

The crown angle can be measured using specialized tools and instruments in a gemological laboratory. It is often included in a diamond’s grading report (such as those provided by the GIA or DCLA), where the diamond’s cut quality is assessed.
Cut Proportions and Overall Performance:

The crown angle is part of the overall cut grade, which also considers other factors like table size, pavilion depth, and girdle thickness. These factors work together to determine the diamond’s overall brilliance and visual appeal.
A diamond with an excellent cut will have a crown angle that complements the pavilion angle, creating a balanced and well-proportioned stone that maximizes light performance.
How the Crown Angle Affects Diamond Quality:
A diamond’s cut quality is considered the most important factor in determining its overall appearance, often more important than its carat weight, colour, or clarity. A diamond with an optimal crown angle is more likely to have exceptional light performance, ensuring the diamond sparkles brilliantly.

In diamond grading reports, such as those from the DCLA (Diamond Certification Laboratory of Australia) or GIA (Gemological Institute of America), the crown angle is used to evaluate the diamond’s cut quality and assess how well it will reflect light.

Summary of Ideal Crown Angle:
Round Brilliant Cut: Ideal crown angle is typically between 34° and 35° for maximum brilliance.
The crown angle works in conjunction with other factors, like the pavilion angle, to influence the diamond’s overall light performance.
If you’re considering purchasing a diamond, the crown angle is a crucial factor to keep in mind when evaluating the overall cut quality, as it directly affects how much sparkle and brilliance the diamond will exhibit.

The crown height of a diamond refers to the vertical measurement of the crown portion of the diamond, which is the area above the girdle (the widest part of the diamond). It is one of the key proportions that affects a diamond’s overall cut quality and visual appearance. The crown height plays a significant role in how well a diamond reflects light and how its sparkle is perceived.

Key Points About Diamond Crown Height:
Crown Height and Overall Cut:

The crown height is an important part of a diamond’s cut proportions, which determine how well the diamond will perform in terms of brilliance, fire, and scintillation.
The height of the crown is usually expressed as a percentage of the overall depth of the diamond. The depth is the total height of the diamond from the culet (bottom point) to the table (top flat surface).
Crown Height Proportions:

For a round brilliant diamond, the ideal crown height is typically between 12% and 16% of the total depth.
A crown height that is too shallow can cause the diamond to appear flat, as light may escape from the sides, reducing its brilliance and sparkle.
A crown that is too tall can make the diamond appear top-heavy, and it might lead to light leakage from the bottom of the diamond, affecting its overall light performance.
Crown Height and Brilliance:

The crown height affects the angle of the crown facets and, consequently, the way light enters and exits the diamond. Proper crown height ensures that light is reflected and refracted optimally within the stone, creating the sparkle and brilliance diamonds are known for.
When the crown height is proportioned correctly, it maximizes light return, ensuring that the diamond exhibits bright flashes of light and vibrant colours (fire).
Impact of Crown Height on Visual Appearance:

Shallow Crown Height: A crown that is too shallow may cause the diamond to look less vibrant and may reduce its overall brightness. Light can escape from the sides, diminishing the diamond’s sparkle.
Tall Crown Height: A crown that is too tall can make the diamond look overly deep or heavy, which can reduce the amount of light returning through the top of the diamond, leading to a darker appearance.
Relationship with Pavilion Angle:

The crown height is often considered alongside the pavilion angle (the angle of the lower portion of the diamond) to determine the diamond’s overall light performance. The crown and pavilion work together to reflect light properly inside the diamond, and the proportions of these angles must complement each other for optimal results.
Crown Height in Grading:

When diamonds are graded by gemological laboratories like GIA or DCLA, the crown height is taken into consideration as part of the overall cut grade. A well-proportioned crown height helps achieve a grade of Excellent or Ideal in terms of cut quality, which is a critical factor in a diamond’s value and appearance.
Ideal Crown Height:

For a round brilliant cut, an ideal crown height typically falls between 12% and 16% of the total diamond depth.
This range ensures that the crown is tall enough to allow proper light reflection, but not so tall that it causes light leakage or reduces overall brightness.
Summary of Diamond Crown Height:
Crown Height: The vertical measurement from the girdle to the table of the diamond.
Ideal Proportion: For round brilliant diamonds, the crown height is ideally between 12% and 16% of the diamond’s total depth.
Impact on Light Performance: A properly proportioned crown height ensures the diamond reflects light optimally, producing maximum brilliance and sparkle.

The diamond crown height percentage refers to the ratio of the height of the crown (the top portion of the diamond) relative to the total depth of the diamond. This percentage is a key factor in evaluating the cut quality of a diamond and has a direct impact on how well the diamond reflects light, which in turn affects its brilliance and fire.

Ideal Crown Height Percentage:
For a round brilliant cut diamond, the ideal crown height typically falls between 12% and 16% of the total depth of the diamond.
12% to 16% is considered the sweet spot because this range ensures that the crown is appropriately proportioned to maximize light return and optimize brilliance.
How to Calculate Crown Height Percentage:
The crown height percentage is calculated by dividing the height of the crown by the total depth of the diamond, then multiplying the result by 100.

Crown Height Percentage=(Total DepthCrown Height​)×100

Impact of Crown Height Percentage on Diamond Appearance:
Too Shallow: A crown height percentage that is too low (e.g., below 12%) can result in a diamond that looks flat and lacks brilliance. This is because light may escape through the sides of the diamond, reducing its sparkle.

Too Tall: A crown height percentage that is too high (e.g., above 16%) may make the diamond look overly deep or top-heavy, potentially reducing its overall brightness as light leaks out of the bottom, rather than returning through the table.

Ideal Proportion: Diamonds with a crown height percentage within the 12%-16% range tend to have the optimal balance of light reflection, maximizing both brilliance and fire. These diamonds typically appear vibrant and well-proportioned.

Crown Height and Other Proportions:
While crown height is crucial, it should not be considered in isolation. It works in conjunction with other cut proportions, such as:

Pavilion angle (the angle of the lower portion of the diamond)
Table size (the flat surface on top of the diamond)
Girdle thickness (the outermost edge of the diamond)
For the best light performance, all these proportions need to complement each other. A well-proportioned crown height enhances the overall cut quality and brilliance of the diamond, contributing to its desirability and value.

Summary:
Crown Height Percentage: The ratio of the crown height to the total depth of the diamond.
Ideal Range: The ideal crown height percentage for a round brilliant diamond is typically between 12% and 16%.
Impact on Brilliance: An ideal crown height percentage ensures maximum light return, producing a diamond with optimal sparkle and brilliance.

An internal crystal in a diamond refers to a type of inclusion (a naturally occurring characteristic inside the diamond). These crystals can be small mineral particles or other forms of inclusions trapped within the diamond during its formation deep within the Earth. Internal crystals are often used by gemologists to identify a diamond and can have an impact on the diamond’s appearance, clarity, and value.

Key Points about Internal Crystals in Diamonds:
Types of Internal Crystals:

Mineral Crystals: These are the most common type of internal crystals found in diamonds. They are usually small mineral particles that were trapped inside the diamond during its formation. These mineral crystals could be made of other minerals like garnet, peridot, or even graphite.
Diamond Crystals: Occasionally, diamonds may contain tiny crystals of diamond itself within them. These are rare but can appear as inclusions that look like tiny diamonds or clusters of diamond particles within the main diamond.
Other Inclusions: Other forms of inclusions, such as feathers, clouds, or blotches, might also contain internal crystals, but these are less common.
Impact on Clarity:

Clarity Grade: Internal crystals are considered inclusions, and they affect a diamond’s clarity grade. The presence of these inclusions can lower the clarity rating of a diamond, especially if the crystal is large, visible to the naked eye, or affects the overall appearance of the stone.
Diamonds are graded on clarity from Flawless (FL) to Included (I) based on the visibility and size of these internal characteristics. The larger and more noticeable the crystal, the more it can impact the clarity grade.
Visible Internal Crystals:

Inclusions Visibility: Some internal crystals may be visible to the naked eye, especially if they are large or located near the surface of the diamond. In other cases, they may be microscopic and only visible under magnification.
Location: The location of the internal crystal inside the diamond also plays a role in its visibility. If it’s near the surface, it may cause the diamond to have blemishes on the surface (as the crystal could potentially cause a chip or fracture if it’s not cut properly).
Internal Crystals and Diamond Value:

Negative Impact on Value: Larger, visible internal crystals generally decrease a diamond’s value, as they affect the clarity grade and overall appearance. The more inclusions there are inside the diamond, the lower the diamond’s clarity and value.
Exceptions: Sometimes, small internal crystals that are not visible to the naked eye may have little to no effect on the diamond’s appearance or value. In some cases, they might even add uniqueness to the diamond, especially if they are particularly small or unique in appearance.
Internal Crystals and Diamond Identification:

Unique Fingerprints: Every diamond contains its own unique combination of inclusions, including internal crystals, which makes diamonds identifiable. Gemologists use these characteristics, known as the diamond’s “fingerprint,” to confirm the diamond’s authenticity and traceability.
Laser Inscriptions: Some diamonds may have laser inscriptions on the girdle (the outer edge of the diamond) that record a unique identification number, which can be cross-referenced with a diamond’s internal characteristics and certificate.
Crystal Inclusions in Fancy Color Diamonds:

In fancy color diamonds, the presence of internal crystals can sometimes enhance or influence the overall color appearance of the diamond. For example, certain internal inclusions might give the diamond a different hue or intensity of color, particularly in diamonds with natural color variations like pink, blue, or green.
Crystal Inclusions and Durability:

The impact of internal crystals on a diamond’s durability depends on their size and location. While diamonds are incredibly strong and durable, large internal crystals near the surface may create weaknesses or make the diamond more prone to breaking or chipping.
Smaller internal crystals that are positioned away from the surface tend to have little impact on the diamond’s durability.
Summary:
Internal Crystal: An inclusion made up of a small mineral or diamond particle trapped inside the diamond during its formation.
Effect on Clarity: Internal crystals can lower a diamond’s clarity grade, especially if they are large or visible to the naked eye.
Identification: Internal crystals can act as a unique “fingerprint” for identifying a diamond.
Impact on Value: Larger, visible internal crystals can decrease the value of a diamond, though small, microscopic crystals may not have much impact.
Durability: Internal crystals near the surface can weaken the diamond and increase the risk of chipping.

Cubic Zirconia (CZ) is a synthetic gemstone that is often used as a diamond simulant. It is made from zirconium dioxide (ZrO₂) and is commonly used in jewelry as an affordable alternative to diamonds due to its striking resemblance to them.

Key Points about Cubic Zirconia:
Composition:

Cubic zirconia is composed of zirconium dioxide and is typically created through a synthetic process. The crystal structure of cubic zirconia is cubic, which is where it gets its name from.
Cubic zirconia is artificially manufactured in laboratories, making it more affordable and accessible compared to diamonds, which are naturally occurring.
Appearance:

Cubic zirconia is colorless and has a similar brilliance and sparkle to diamonds, which is why it’s often used in jewelry as a diamond substitute.
It can also be created in a variety of colors, such as pink, blue, green, and others, by adding different metal oxides during the manufacturing process.
While CZ can appear similar to a diamond at first glance, it lacks the same level of fire (colored light dispersion) and is generally less durable than a diamond.
Durability:

One of the biggest differences between cubic zirconia and diamonds is their hardness. Cubic zirconia has a hardness of 8 to 8.5 on the Mohs scale, whereas diamonds are the hardest natural substance, scoring a 10.
Because of this, cubic zirconia is more prone to scratching and wearing down over time, especially when compared to diamonds, which maintain their shine and surface integrity much longer.
Weight:

Cubic zirconia is heavier than diamonds. This means that a cubic zirconia stone of the same size will weigh more than a diamond of the same size. This weight difference can sometimes be noticeable when comparing stones of similar size and shape.
Cost:

Cubic zirconia is significantly more affordable than diamonds. While the price of diamonds can be quite high due to their rarity and the complexities involved in their formation, cubic zirconia is a much cheaper option and is widely available.
CZ is commonly used in fashion jewelry, where the appearance of a diamond is desired, but the cost of an actual diamond is not necessary or desired.
Clarity:

Cubic zirconia is often created in a way that makes it free of inclusions or very clean in appearance. Unlike natural diamonds, which often contain inclusions (called blemishes or inclusions), cubic zirconia typically has perfect clarity.
While diamonds can have unique inclusions that add to their value and identity, CZ’s flawless appearance can sometimes be a disadvantage in terms of authenticity because it lacks the natural imperfections that make diamonds unique.
Uses:

Jewelry: Cubic zirconia is often used in rings, earrings, necklaces, and bracelets as a diamond substitute. It’s particularly popular in engagement rings, wedding bands, and costume jewelry.
Affordable Alternative: People who want the appearance of a diamond but don’t want to spend the high cost may choose cubic zirconia as an alternative.
Optical Properties:

Brilliance: Cubic zirconia is known for its high brilliance (sparkle), as it reflects light well, similar to diamonds. However, it has a higher dispersion than diamonds, which means it can exhibit more colorful flashes of light, often seen as a rainbow effect.
Fire: Although cubic zirconia has more fire than a diamond, it is generally considered less desirable in this regard compared to the subtle, refined fire diamonds produce.
Maintenance:

Since cubic zirconia is softer and more prone to scratching, it may require more care and maintenance than diamonds. Over time, CZ can lose its luster due to scratches and build-up of oils and grime.
Regular cleaning is recommended to maintain its appearance, and it’s advised to store cubic zirconia jewelry separately to prevent scratches.
Distinguishing from Diamonds:

Despite its close resemblance to diamonds, there are several ways to distinguish cubic zirconia from diamonds, such as by examining the weight, hardness, fire, and brilliance.
Gemological Testing: Professional gemologists use specific tools, like a diamond tester or refractive index measurement, to accurately identify cubic zirconia from diamonds.
Summary:
Cubic Zirconia (CZ): A synthetic gemstone made from zirconium dioxide, used as a diamond simulant due to its similar appearance but lower cost.
Hardness: CZ has a hardness of 8-8.5 on the Mohs scale, much lower than diamonds (10), making it more susceptible to scratches.
Appearance: CZ is colorless and exhibits a high level of brilliance, but it has more fire than diamonds, often appearing to have more colorful flashes of light.
Cost: CZ is much more affordable than diamonds, making it a popular choice for fashion jewelry and costume pieces.
Durability: Less durable than diamonds due to its lower hardness, CZ can wear down and scratch more easily.

The diamond culet is the flat surface at the very bottom of the diamond, specifically at the pavilion’s tip. It plays a role in the diamond’s overall appearance, cut quality, and how it interacts with light.

Key Points about the Diamond Culet:
Location:

The culet is located at the very bottom of the diamond, at the pavilion, which is the lower portion of the diamond beneath the girdle.
It forms part of the cut and is essentially the small facet at the apex of the pavilion, where the diamond tapers to a point (in traditional cuts like round brilliant).
Function:

Purpose: The culet serves to prevent the diamond from being damaged during the cutting process. If the point of the pavilion were left unpolished or sharp, it could easily chip or break. The culet helps avoid this by giving the diamond a flat surface at the tip.
Light Interaction: The culet doesn’t significantly affect the light return or brilliance of the diamond, but its size and presence can influence the appearance of the diamond from the bottom.
Culet Size:

None: Some diamonds are cut without a culet at all, especially if the diamond has a sharp, pointed pavilion (this is often seen in high-quality round brilliant cuts). These diamonds may be labeled as “no culet” or “culet: none” in grading reports.
Small: A small culet is typically 0.1% to 0.3% of the diameter of the diamond. This is most common in diamonds cut for optimal brilliance.
Medium, Large, or Very Large: Larger culets are rare but can be found in older or antique diamonds, as well as some cushion or asscher cuts. Larger culets can sometimes give the diamond an unusual look and may reduce the diamond’s overall brilliance and desirability.
Impact on Diamond’s Appearance:

A larger culet may be visible from the top of the diamond, especially in diamonds with a larger table or shallow cut. It can detract from the diamond’s brilliance by allowing light to escape more easily.
A small culet or no culet at all is generally preferred in modern diamond cuts, as it maintains the maximum light performance and enhances the sparkle.
Culet and Clarity:

A large culet can sometimes be considered an inclusion when graded for clarity, as it may affect the overall symmetry of the diamond. However, a small or no culet typically doesn’t affect the diamond’s clarity.
The size and presence of the culet are typically noted in a diamond’s grading report, but it is not a major factor in the diamond’s clarity grade unless it affects the overall symmetry or appears as a significant visible feature.
Culet and Cut Quality:

While the culet doesn’t directly influence the light performance or brilliance, the proportions and symmetry of the cut, including the culet, are important for achieving an optimal cut grade.
Symmetry: A well-formed, symmetrical culet contributes to the diamond’s overall cut quality, enhancing its visual appeal.
Summary:
The diamond culet is the small flat facet at the tip of the diamond’s pavilion, designed to prevent damage during the cutting process.
Culet Size: It can be absent (no culet), small, medium, or large, with smaller culets generally preferred for better light return and brilliance.
Impact on Appearance: A larger culet may be visible from the top and can reduce the diamond’s sparkle. A small culet or no culet is preferred in modern cuts.
Clarity and Symmetry: The size of the culet can affect the diamond’s clarity and symmetry, but typically does not impact overall clarity unless it’s large or noticeably visible.

The cushion cut diamond is a popular diamond shape known for its rounded edges and square or rectangular outline, giving it a distinctive pillow-like appearance. This cut is a blend of the classic round shape and the square shape, offering a balance of both styles. It has been a beloved cut for centuries and has seen a resurgence in recent years, particularly in engagement rings.

Key Features of the Cushion Cut Diamond:
Shape:

The cushion cut diamond is typically square or rectangular, with rounded corners that resemble a pillow (hence the name). It can come in various ratios, where the length-to-width ratio determines whether the diamond appears more square or more rectangular.
The rounded corners give the cushion cut its soft and vintage look, making it a timeless and romantic choice.
Facets:

The cushion cut has a unique facet structure compared to other cuts. It often has 58 facets (the same as the traditional round brilliant cut), though some variations, such as the modified cushion cut, may have additional facets to enhance brilliance.
The facets on a cushion cut diamond create a larger, more noticeable sparkle, with the light bouncing around the stone in a way that gives it a vintage yet brilliant shine.
Types of Cushion Cut:

Standard Cushion Cut: The traditional cushion cut, with rounded corners and soft edges.
Modified Cushion Cut: A variation that uses additional facets to enhance brilliance. It can be cut with a modern look, featuring sharper corners and a more contemporary style.
Cushion Brilliant Cut: A cushion cut with a modern, brilliant-style facet arrangement, designed for maximum sparkle.
Appearance:

Cushion cut diamonds are known for their soft, romantic glow and are often preferred for their vintage and classic look. This cut is ideal for those who like the glitter of the round brilliant but want something that feels more unique and timeless.
Depending on the specific facet arrangement and cutting style, the cushion cut can have a brilliant appearance, creating a large amount of sparkle and fire, or a antique-style appearance with a more subdued, charming glow.
Popularity:

The cushion cut is especially popular in engagement rings, particularly for those who want a vintage or antique-inspired design. It has also been a favorite among celebrities and is seen in many high-profile engagements.
The cut’s resurgence in popularity is partly due to its combination of classic beauty and modern brilliance.
Durability:

The cushion cut diamond is generally quite durable because of its rounded corners. These corners are less prone to chipping compared to the sharp edges of other cuts, such as the emerald or asscher cuts.
The diamond’s pavilion depth (how deep it is from the table to the culet) can affect its overall durability and brilliance, so a well-proportioned cushion cut will ensure the diamond lasts over time.
Choosing the Right Cushion Cut:

Length-to-Width Ratio: The length-to-width ratio is a key consideration when selecting a cushion cut diamond. A ratio of 1.00 will result in a perfectly square cushion, while ratios above or below 1.00 will create a rectangular cushion shape. The ratio will influence the diamond’s overall appearance and is a matter of personal preference.
Cut Quality: The quality of the cut will have a significant effect on the diamond’s brilliance. Cushion cuts can be brilliant (emphasizing sparkle) or antique-style (more muted and charming). Look for diamonds with excellent or very good cut grades to ensure optimal light reflection and sparkle.
Clarity and Color: While cushion cut diamonds can hide inclusions and color better than other cuts due to their larger facets and the faceted structure, it is still important to check for clarity and color before purchasing.
Ideal Settings for Cushion Cut Diamonds:

Halo Setting: A cushion cut diamond in a halo setting (surrounded by smaller diamonds) is particularly popular, as it amplifies the appearance of the main diamond and adds extra sparkle.
Vintage and Classic Settings: The cushion cut diamond fits perfectly into vintage-style or antique-inspired rings, often with intricate detailing or milgrain edges around the band.
Solitaire Settings: Many people opt for a solitaire setting (a single diamond on the band) for a cushion cut diamond, allowing the diamond to be the main focus.
Brilliance and Sparkle:

The cushion cut is known for its good sparkle due to the faceting structure, but it may not exhibit the same level of fire (colored light reflections) as round brilliant cuts.
The brilliance of the cushion cut comes from the way light interacts with the larger facets. A well-cut cushion can shine brightly and produce beautiful flashes of light.
Cushion Cut vs. Other Cuts:

Round Brilliant vs. Cushion Cut: While round brilliant diamonds are typically the most brilliant (sparkling) due to their specific facet pattern, cushion cuts can offer similar sparkle with a softer, more vintage look.
Princess Cut vs. Cushion Cut: Princess cuts are square-shaped with sharp edges, providing a modern and angular look, while cushion cuts offer a softer, more rounded feel. The choice depends on personal style preferences.

Diamond Cut or Proportion refers to the quality of a diamond’s shape and symmetry, which directly influences its brilliance, fire, and overall aesthetic appeal. It’s one of the most important aspects of diamond grading and is separate from the diamond’s shape (e.g., round, princess, cushion). The cut is all about how well the diamond has been crafted and faceted from the rough stone, and how this craftsmanship maximizes its ability to reflect light.

Key Aspects of Diamond Cut/Proportion:
What is Diamond Cut?

Diamond Cut refers to how well a diamond has been shaped and faceted to reflect light, which impacts the diamond’s sparkle.
It involves the proportions (depth, width, angles) of the diamond and how they affect the way light enters, bounces around, and exits the diamond.
Cut does not refer to the diamond’s shape (such as round or square), but rather to the quality of the cutting process, including the diamond’s facets, symmetry, and polish.
The Importance of Cut:

A well-cut diamond reflects light more effectively, creating maximum sparkle and brilliance. A poorly cut diamond, even if it is of high-quality material, may appear dull or lifeless.
A well-cut diamond allows for optimal light performance. Light enters the diamond, reflects off the facets, and exits the top, creating a brilliant sparkle.
The 4 Cs and Cut:

The 4 Cs of diamond grading—Cut, Clarity, Colour, and Carat weight—are all important, but cut is often considered the most significant factor for a diamond’s visual appeal.
A diamond can be flawless in clarity and color, but if the cut is poor, it will not shine as brilliantly as a well-cut diamond.
Grading the Cut:

Ideal Cut: Diamonds with an “Ideal” cut are the best of the best, exhibiting maximum brilliance, fire, and sparkle.
Excellent Cut: Excellent cut diamonds also reflect light well and are often used interchangeably with “Ideal” cut in many grading reports.
Very Good Cut: A very good cut diamond still has excellent light performance, but there may be minor compromises in proportions compared to Ideal or Excellent.
Good Cut: Good cut diamonds still show decent sparkle, but they may not have as much brilliance as those graded Excellent or Ideal.
Fair and Poor Cuts: These diamonds lack the brilliance and sparkle that higher-quality cuts offer. Light is lost through the sides or bottom, resulting in a less brilliant appearance.
Key Elements of Cut/Proportion:

Table: The flat top surface of the diamond. The table size affects how much light is reflected inside the diamond.

Ideal Table Size: The table should typically be between 53-58% of the diamond’s diameter. A table that’s too large can cause light to leak out the bottom, and a table that’s too small may cause the diamond to appear dark or dull.
Depth: The height of the diamond from the culet to the table.

Ideal Depth: A diamond’s depth percentage (height divided by diameter) should fall between 59-62.5%. If the depth is too shallow, light will escape from the bottom, making the diamond less brilliant. If it’s too deep, light will exit from the sides, resulting in a dimmer appearance.
Crown Angle: The angle at which the upper portion (crown) of the diamond is cut. This influences how light enters and reflects within the diamond.

Ideal Crown Angle: For round brilliant diamonds, an ideal crown angle is generally between 34-35 degrees.
Pavilion Angle: The angle of the diamond’s lower portion, from the girdle to the culet. This also affects how light enters the diamond and contributes to its overall brilliance.

Ideal Pavilion Angle: Around 40.6-41.2 degrees for a round brilliant diamond.
Girdle: The outer edge of the diamond, where the top (crown) and bottom (pavilion) meet.

Ideal Girdle: The girdle should be neither too thick nor too thin, as extremes can affect the durability and light performance of the diamond.
Symmetry and Polish:

Symmetry refers to the precision of the diamond’s facets and how well they align. Good symmetry ensures that light is evenly reflected, contributing to the diamond’s brilliance.
Polish refers to the smoothness of the diamond’s surfaces. The better the polish, the more light the diamond can reflect.
Cut and Diamond Shapes:

The cut will vary slightly depending on the diamond shape. For example:
Round Brilliant Cut: Known for its excellent light reflection and maximum brilliance due to its specific proportions and symmetry.
Princess Cut: Features a square shape with sharp edges and also requires precise cutting for optimal brilliance.
Emerald Cut: Has a rectangular shape with a large table and fewer facets, focusing on clarity rather than brilliance.
Cushion Cut: Features rounded corners and is often designed with a more antique-style cut, which can affect its overall sparkle and brilliance.
Diamonds and Their Light Performance:

A diamond’s ability to perform with light is often referred to as its fire (the dispersion of light into rainbow colors), brilliance (the white light reflected from the diamond), and scintillation (the flashes of light as the diamond moves).
The cut of the diamond directly influences these factors. The angles, proportions, and symmetry all contribute to how effectively the diamond performs with light.
Evaluating Diamond Cut:

Ideal and Excellent cuts provide the best overall appearance and maximum brilliance.
A diamond with a good cut still offers decent brilliance but may be a bit less fiery or sparkly than an Ideal or Excellent cut diamond.
It’s crucial to evaluate a diamond’s cut based on specific cut grading criteria from a reputable grading laboratory like GIA, which assigns cut grades to diamonds based on measurements and performance.
Summary:
The diamond cut (or proportion) determines how a diamond interacts with light, influencing its brilliance, fire, and overall sparkle.
Key elements that affect cut include table size, depth, crown angle, pavilion angle, girdle thickness, and the overall symmetry and polish.
The cut has the most significant impact on a diamond’s appearance compared to other characteristics like clarity or colour, and diamonds with excellent cuts will appear the most vibrant and brilliant.
Grading: Diamonds are graded for cut as Ideal, Excellent, Very Good, Good, Fair, or Poor, based on their proportions, symmetry, and light performance.

Diamond Cut Grade is a key factor in determining a diamond’s overall beauty and value. It assesses how well a diamond has been shaped and faceted to maximize its ability to reflect light, creating brilliance and sparkle. A diamond’s cut grade is different from its shape (such as round, square, or oval) because it refers specifically to the quality of the craftsmanship involved in shaping and faceting the stone.

The Key Elements of Diamond Cut Grade:
Proportions:

The proportions of the diamond include the ratio of the table size (top flat surface), depth (the height of the diamond), and the girdle (the outer edge). These proportions must be balanced to ensure that light can enter, reflect, and exit the diamond optimally.
Symmetry:

Symmetry refers to how well the facets are aligned and arranged. Proper symmetry allows light to reflect evenly across the surface of the diamond, contributing to its brilliance.
Finish:

Finish refers to the quality of the polishing process. The finer the polish, the more light the diamond can reflect, enhancing its sparkle.
Diamond Cut Grades:
The cut grade can range from Excellent to Poor based on how well the diamond’s proportions, symmetry, and finish meet the ideal criteria. The scale used by most grading labs, including DCLA, is as follows:

Excellent Cut:

Diamonds with an Excellent Cut are considered the best. These diamonds reflect light in the most brilliant and dazzling way.
They have precise proportions, ideal symmetry, and a flawless polish, maximizing the sparkle and brilliance.
Ideal for: Those seeking the best possible appearance in terms of light performance.
Very Good Cut:

A Very Good Cut diamond reflects almost as much light as an Excellent Cut diamond, with only slight imperfections in the proportions or symmetry.
These diamonds still exhibit excellent brilliance, but may lack the extreme precision of an Excellent Cut.
Ideal for: Those who want a high-quality diamond at a slightly more affordable price point.
Good Cut:

A Good Cut diamond has visible differences in proportions, which can affect the diamond’s light reflection, but it still looks attractive with decent sparkle.
These diamonds may not exhibit the same level of brilliance as the top grades, but they offer good value.
Ideal for: Budget-conscious buyers who still want a well-cut diamond.
Fair Cut:

A Fair Cut diamond has more noticeable issues with proportions and symmetry that can reduce its ability to reflect light.
While still a diamond, it may appear less brilliant and duller than diamonds with higher cut grades.
Ideal for: Those seeking a lower-priced diamond, though it may not be the best in terms of light performance.
Poor Cut:

A Poor Cut diamond exhibits significant issues with proportions, symmetry, or polish, leading to poor light reflection and diminished brilliance.
The sparkle and fire are significantly reduced compared to higher-grade diamonds.
Ideal for: Typically, diamonds graded as Poor Cut are not recommended for purchasing, as they do not offer good visual appeal.
Factors That Influence Diamond Cut Grade:
Table Size: The table is the flat top facet of the diamond. If it’s too large or too small, it can affect the diamond’s brilliance.

Ideal Table Size: Typically between 53%-58% of the total diameter of the diamond.
Depth: The depth is the height of the diamond from the table to the culet. The depth percentage is the ratio of the diamond’s depth to its diameter.

Ideal Depth: Between 59%-62.5%.
Crown Angle: The crown is the upper portion of the diamond above the girdle. The crown angle influences how light is reflected from the diamond.

Ideal Crown Angle: Typically between 34-35 degrees for round brilliant cuts.
Pavilion Angle: The pavilion is the lower part of the diamond beneath the girdle. The pavilion angle helps determine how well the diamond reflects light.

Ideal Pavilion Angle: Around 40.6-41.2 degrees for round brilliant diamonds.
Girdle Thickness: The girdle is the outer edge of the diamond, and it should neither be too thin nor too thick.

Ideal Girdle Thickness: Neither too thin nor too thick, which allows for proper durability and light reflection.
Symmetry: Symmetry refers to how well the diamond’s facets match and align. Good symmetry ensures consistent light reflection and enhances the overall sparkle of the diamond.

Polish: The finish or smoothness of the diamond’s facets affects how light travels and reflects. A smooth and well-polished diamond reflects more light and appears more brilliant.

The Role of Cut in Diamond Value:
Cut is the most important factor in a diamond’s appearance. While colour, clarity, and carat weight are important, a poorly cut diamond will not appear as brilliant as a well-cut diamond, regardless of its other attributes.
A diamond’s cut grade can significantly impact its price. Diamonds with Excellent or Ideal cuts are typically more expensive due to their superior light performance and visual appeal.
DCLA’s Diamond Cut Grading:
The Diamond Certification Laboratory of Australia (DCLA) follows the international cut grading standards and provides a detailed analysis of a diamond’s cut, including the table size, depth, crown and pavilion angles, symmetry, and finish.
DCLA uses advanced gemological tools to measure and grade diamonds with precision, ensuring that each diamond receives an accurate and reliable cut grade.

Diamond Cut for Weight refers to the practice of adjusting a diamond’s proportions to maximise its weight, sometimes at the expense of optimal cut quality. This process is typically seen when a diamond is cut to a specific carat weight, and the diamond’s proportions are altered to retain as much weight as possible from the original rough diamond. While it’s important to understand that this does not necessarily mean the diamond is cut poorly, the cut for weight can affect the diamond’s overall brilliance, sparkle, and light performance.

How Cut for Weight Affects a Diamond:
Weight Preservation:

Diamond cutters aim to preserve as much weight as possible from the original rough diamond. In some cases, this means making the diamond deeper or shallower than ideal to keep the carat weight intact.
A diamond that is cut to maximise weight may have proportions that are not ideal for light reflection, leading to less brilliance compared to a diamond cut to ideal proportions.
Depth vs. Table Size:

Shallow cuts (where the diamond is cut too wide with less depth) or deep cuts (where the diamond is cut very deep with a small table) are common in diamonds that are cut for weight.
Shallow-cut diamonds tend to have a larger table size, making them appear larger face-up, but they often lack brilliance since light escapes from the bottom rather than being reflected within the diamond.
Deep-cut diamonds may appear smaller for their weight because the table appears smaller, but they can reflect less light, leading to a less vibrant appearance.
Cut for Weight and Diamond Shape:

When cutting diamonds for weight, it is common to see a variety of shapes, including round and princess cuts, but some shapes are more prone to cut for weight than others.
For example, round brilliant diamonds are often cut for weight in ways that sacrifice the ideal proportions, leading to either a shallow or deep cut. Similarly, emerald cuts and asscher cuts may also be cut for weight, leading to larger faces with less depth.
Trade-offs Between Weight and Quality:

Cutting for weight can be a trade-off between achieving a desired carat weight and ensuring the diamond has optimal proportions to maximise its brilliance.
A well-cut diamond with excellent proportions will typically have the best brilliance and sparkle, but it may not be as large as a diamond that has been cut to maximise weight.
Light Reflection and Brilliance:

The cut quality of a diamond is directly linked to how well it reflects light. Ideal cut diamonds are designed to reflect as much light as possible, creating that sought-after brilliance and sparkle.
Diamonds cut for weight often have a lower cut grade because the proportions are not ideal for light performance, which can lead to a duller appearance.
Carat Weight vs. Appearance:

While diamonds cut for weight may appear larger due to the size of the table or girdle, they may not look as brilliant or sparkly as diamonds with ideal cuts. The key consideration is whether a larger diamond, cut for weight, is worth more to the buyer than one that is smaller but has superior light performance.
Choosing Between Weight and Quality:

Many buyers prefer diamonds that are cut to ideal proportions (even if they are slightly smaller in carat weight), as these diamonds offer superior brilliance and visual appeal.
If a buyer is looking for a specific carat weight, the trade-off may involve a less-than-ideal cut for weight.
The Importance of Cut Over Carat Weight:
When choosing a diamond, the cut often takes precedence over the carat weight in determining the overall beauty and value of the stone. A well-cut diamond, even if slightly smaller in weight, will typically appear more brilliant and attractive than a larger diamond with suboptimal proportions.
Diamonds that are cut for weight might appear larger or offer a higher carat weight, but their light performance and sparkle may be compromised.
How DCLA Evaluates Cut for Weight:
DCLA (Diamond Certification Laboratory of Australia) evaluates diamonds based on their cut quality rather than just focusing on weight. A DCLA report will provide precise details on the diamond’s proportions, symmetry, and polish, allowing buyers to understand the impact of weight-cutting decisions on the diamond’s appearance.
DCLA grades diamonds on cut based on a full spectrum of light performance analysis, including brilliance, fire, and scintillation. This is important because diamonds cut for weight may appear less brilliant, even if they weigh more.
Key Takeaways for Buyers:
Carat weight does not necessarily equate to a more beautiful diamond if the cut is compromised.
Diamonds cut for weight may have shallow or deep proportions that diminish brilliance.
It is generally better to prioritise a well-cut diamond with ideal proportions over a diamond that has been cut to maximize weight.
Always request a DCLA grading report to ensure that you understand the full cut quality, even when prioritising weight.
If you’re considering a diamond, it’s crucial to balance weight preferences with an understanding of the diamond’s cut quality and how it affects the diamond’s overall appearance. Would you like further guidance on understanding diamond proportions and how to select the best-cut diamond for your needs?