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Hearts & Arrows

Hearts and Arrows

A Symbol of Precision and Symmetry in Diamonds
The term Hearts & Arrows refers to a distinct and beautiful pattern that appears in some high-quality diamonds, primarily those with round brilliant cuts and, occasionally, square cushion cuts. This pattern is the result of exceptional symmetry and precision in the diamond’s cut, showcasing the alignment of the facets in such a way that a specific visual effect is created when the diamond is viewed from certain angles.

Understanding the Hearts & Arrows Pattern
When a diamond is perfectly cut with optimal symmetry, it can display the Hearts & Arrows pattern, which is best seen when the diamond is viewed under magnification. The pattern consists of eight arrowheads visible when viewed from above (through the crown) and eight heart shapes visible when viewed from below (through the pavilion).

Key Characteristics of Hearts & Arrows:
Eight Arrowheads – When viewed through the crown (the top portion of the diamond), the facets create a symmetrical pattern that appears as eight arrow-shaped figures. This configuration is due to the alignment of the table facet with the eight main facets surrounding it.
Eight Heart Shapes – When viewed through the pavilion (the bottom part of the diamond), the same alignment of facets produces eight heart-like shapes, arranged symmetrically around the centre. These shapes appear because of the reflection of the facets from the pavilion and the crown.
Perfect Symmetry – The creation of the Hearts & Arrows pattern is a result of a perfectly symmetrical diamond cut. The precision required to achieve this pattern is indicative of a high-quality diamond cut.
Hearts & Arrows and Diamond Cut Quality
While the Hearts & Arrows pattern is a hallmark of symmetry and precision, it does not necessarily indicate that the diamond is of the highest cut grade, such as an Ideal Cut. Instead, it simply means that the diamond has exceptional faceting and is well-aligned, which contributes to its overall visual appeal.

Cut Quality and Symmetry
Ideal Cut Diamonds often display the Hearts & Arrows pattern, though not every Ideal Cut will exhibit it. The pattern itself is a result of careful and meticulous cutting, with a focus on achieving perfect symmetry, which enhances both the brilliance and fire of the diamond.
Diamonds with the Hearts & Arrows pattern are often graded as having excellent symmetry but are not automatically classified as Ideal based solely on the appearance of the pattern.
Importance of Symmetry in the Hearts & Arrows Pattern
Symmetry is key to the Hearts & Arrows pattern’s formation. A diamond with this feature indicates that its facets have been cut in perfect alignment, which ensures optimal light performance.
While perfect symmetry enhances a diamond’s brilliance, it is important to remember that the Hearts & Arrows pattern itself does not affect the diamond’s overall colour or clarity.
How Hearts & Arrows Enhances the Diamond’s Appearance
The Hearts & Arrows pattern contributes to the diamond’s overall visual appeal by ensuring that the facets are aligned in such a way that they enhance the diamond’s brilliance and fire.

Brilliance and Fire
The alignment of facets in a diamond that exhibits Hearts & Arrows results in more efficient light reflection, increasing the brilliance of the diamond (the amount of white light returned).
The symmetry ensures that the diamond displays fire, or the dispersion of coloured light, as the light is reflected and refracted through the facets with greater consistency. This enhanced light performance contributes to the diamond’s ability to sparkle in any lighting condition.
Visual Perception
Diamonds that display Hearts & Arrows often appear more radiant and vivid due to the excellent reflection of light from the facets. The precise facet arrangement allows for an even distribution of light, making the diamond sparkle brilliantly from every angle.
How to View the Hearts & Arrows Pattern
To properly observe the Hearts & Arrows pattern, the diamond needs to be viewed under specific conditions and using the right tools. A Hearts & Arrows viewer (a device designed to allow you to view the diamond from specific angles) is typically used to magnify the diamond’s intricate details.

Viewing through the Crown
Looking down at the diamond from above, through the crown, you should see eight arrow-shaped patterns radiating from the centre. This is the primary visual cue for the Hearts & Arrows pattern.
Viewing through the Pavilion
When looking up at the diamond from the pavilion, you should see eight heart shapes, arranged symmetrically. This view showcases the other half of the pattern and is often considered the most striking visual impression of the diamond’s symmetry.
Why Choose a Hearts & Arrows Diamond?
Diamonds with the Hearts & Arrows pattern are highly prized for their exquisite symmetry, which translates into superior light performance and overall beauty. While the pattern itself doesn’t necessarily guarantee an Ideal Cut grade, it does signal that the diamond has undergone careful craftsmanship and is likely to be visually appealing and highly reflective.

Advantages of Hearts & Arrows Diamonds:
Superior Sparkle – The perfect alignment of facets ensures that the diamond exhibits maximum brilliance and fire, making it incredibly eye-catching.
Exceptional Symmetry – The precise symmetry creates a balanced and harmonious appearance, resulting in a diamond that looks perfectly proportioned.
Symbol of Quality – The Hearts & Arrows pattern is often associated with diamonds of the highest craftsmanship, making them highly sought after by collectors and those looking for premium-quality diamonds.

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Hardness

Understanding the Durability of Diamonds

Understanding the Durability of Diamonds
Hardness refers to a material’s resistance to scratching or abrasion. When it comes to diamonds, this property is particularly significant, as diamonds are known for being the hardest naturally occurring material on Earth. The hardness of a material is typically measured using Mohs Scale of Mineral Hardness, which rates materials based on their ability to scratch others.

Diamond’s Position on Mohs Scale
Diamonds score a perfect 10 on the Mohs scale, placing them at the top of the hardness scale.
This means that diamond can scratch all other materials, but it is unable to be scratched by any other known substance.
What Does Diamond Hardness Mean for Practical Use?
The hardness of diamond is one of the key reasons why it is the ideal choice for jewellery, especially in engagement rings and other precious items worn daily.

Key Benefits of Diamond Hardness:
Resistant to Scratching

The extreme hardness of diamonds ensures that they remain sharp and polished for many years without suffering from scratches, which would diminish their beauty and clarity.
This is especially important for diamonds set in jewellery, as they are exposed to wear and tear from daily activities.
Preservation of the Diamond’s Aesthetic Appeal

The ability of diamonds to maintain their brilliance and fire over time is largely attributed to their hardness. Since diamonds resist scratches, they maintain their faceted surfaces and polish, ensuring that the stone continues to reflect light optimally.
Long-Lasting Investment

Hardness contributes to the long-term durability of diamonds, which can be passed down through generations without significant wear. This makes diamonds an ideal choice for heirlooms and family treasures.
Resistant to Common Household Items

Everyday items such as keys, coins, and even some metals can scratch softer gemstones, but they won’t affect the surface of a diamond. This resilience makes diamonds perfect for engagement rings and wedding bands that are worn constantly.
Hardness vs. Toughness: Understanding the Full Picture
While hardness refers to a material’s resistance to scratching, toughness refers to its ability to resist breaking, chipping, or cracking. While diamonds are the hardest material on Earth, they are not the toughest.

Key Differences:
Hardness (measured on Mohs scale) only measures resistance to scratches, not the ability to withstand sudden impacts or stress.
Toughness, on the other hand, is a measure of a material’s ability to absorb energy and deform without fracturing.
Although diamonds are incredibly hard, they are brittle due to their crystalline structure. This means that diamonds can fracture if subjected to sharp impacts or if they experience extreme pressure in the wrong direction, especially along the cleavage planes where the crystal structure is weakest.

Example:
A diamond may resist scratches from a metal object, but it could shatter or chip if struck with a hammer or dropped on a hard surface.

Diamond Toughness and Its Impact on Cutting
When diamonds are being cut or shaped, a gem cutter must consider the diamond’s cleavage planes—the lines where the crystal structure is most likely to break under stress. A diamond is not just cut for its shape but also to preserve its toughness, as these cleaving directions need to be avoided during the cutting process to ensure that the diamond does not chip or break.

Facet Placement: When cutting a diamond, a skilled gem cutter will place the facets in such a way that they avoid the cleavage planes, thereby maintaining both hardness and toughness.

Precision and Care: The process requires great precision, as even the smallest error can result in a flawed or damaged stone.

How Does Diamond Hardness Compare to Other Materials?
Diamonds are not only the hardest gemstone, but also the hardest naturally occurring substance when compared to other materials. Here’s a look at how diamonds compare to other materials on the Mohs scale:

Material Hardness (Mohs Scale)
Diamond 10
Corundum (Ruby, Sapphire) 9
Topaz 8
Quartz 7
Orthoclase Feldspar 6
Apatite 5
Fluorite 4
Apatite 3
Calcite 3
Talc 1
Diamond’s Hardness Advantage

The next hardest material, corundum (rubies and sapphires), ranks at 9 on the scale, meaning diamonds are significantly harder.
Even common materials like glass or steel are much softer than diamonds, which is why diamond is commonly used in cutting tools for other materials.
What Does Diamond Hardness Mean for Jewellery Care?
While diamonds are extremely resistant to scratches, they still require proper care to prevent damage due to impacts or stress. Here are a few tips for ensuring the long-lasting beauty and durability of your diamond jewellery:

Avoid Hard Impacts: While diamonds are the hardest material, they can still chip or break if struck sharply. Be cautious when handling diamonds, especially when they are set in jewellery.
Store Separately: To avoid scratching, store diamonds separately from other jewellery or harder materials. Consider using a soft pouch or compartment in a jewellery box.
Regular Cleaning: Regularly clean your diamond jewellery to remove dirt or oils that could dull its appearance. Avoid abrasive cleaning methods that could scratch the diamond or the setting.

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Graining

The Natural Growth Patterns in Diamonds
Graining refers to faint wavy, hazy, oily, or shadow-like lines that can appear inside a diamond or on its surface. These patterns result from irregular growth and crystallisation during the diamond’s natural formation deep within the Earth. Graining is sometimes referred to as “growth lines” or “growth marks”, and it can affect a diamond’s clarity, transparency, and overall visual appearance.

What Causes Graining in Diamonds?
Diamonds form over millions to billions of years under extreme heat and pressure deep in the Earth’s mantle. However, not all diamonds grow perfectly. Occasionally, crystallographic irregularities occur, leading to graining. These irregularities may be caused by:

Uneven atomic growth – Fluctuations in temperature and pressure can cause the diamond’s crystal structure to develop inconsistencies.
Interrupted crystallisation – When a diamond pauses in its growth and then resumes, it may form internal distortions.
Mineral inclusions or impurities – Elements such as nitrogen or boron present during formation can contribute to the development of visible graining.

Types of Graining in Diamonds
Graining can appear in various forms, affecting both internal clarity and surface quality. The four main types of graining are:

1. Internal Graining
Appears as faint lines, streaks, or wispy distortions within the diamond.
Can be colourless, white, brown, or reflective.
Sometimes mistaken for inclusions but differs as it follows the diamond’s crystal structure rather than being a foreign substance.
2. Surface Graining
Found on the external facets of the diamond.
Can resemble polishing marks, light scratches, or subtle indentations.
May not be visible to the naked eye but can be detected under 10x magnification.
3. Reflective Graining
A more pronounced form of internal graining where light reflects off the growth lines, making them more noticeable.
Can create a slightly hazy or cloudy appearance in certain lighting conditions.
4. Coloured or Dark Graining
Caused by trace elements within the diamond or due to strain in the crystal structure.
Can appear as brown, grey, or dark shadow-like lines.
More commonly found in diamonds with strong fluorescence or high nitrogen content.
How Does Graining Affect a Diamond’s Appearance and Value?
Impact on Clarity

Internal graining can be noted on a grading report, particularly in diamonds with VS (Very Slightly Included) clarity or lower.
If graining is very faint, it may not impact the clarity grade but could still be mentioned in the report.
Impact on Transparency & Brilliance

Strong graining can cause the diamond to appear milky, hazy, or oily, reducing its transparency.
It may affect the way light travels through the diamond, diminishing brilliance and fire.
Impact on Diamond Grading Reports

Independent gemological laboratories such as DCLA, GIA, and IGI may list graining as a comment in the clarity characteristics section of a diamond grading report.
If graining is significant, it may contribute to a lower clarity grade.
Impact on Value

Diamonds with minor or faint graining typically do not experience a significant drop in value.
However, diamonds with heavy graining or visible haziness may be less desirable and priced lower than those with better transparency.
How to Identify Graining in a Diamond
Graining is often invisible to the naked eye but can be detected through:

10x Magnification – Jewelers and gemologists use a loupe or microscope to identify fine growth lines.
Diamond Grading Reports – If present, graining will be noted in the report’s clarity characteristics section.
Lighting Tests – Shining a bright light through the diamond may reveal hazy areas or faint wavy lines.

Can Graining Be Removed or Minimized?
Recutting & Repolishing – Surface graining may be improved by polishing or re-cutting the diamond, but this reduces carat weight.
Proper Cleaning & Maintenance – A clean diamond can help reduce the visual impact of light surface graining.
Choosing a Well-Cut Diamond – A diamond with excellent cut proportions can help mask minor graining by maximizing brilliance.

Is Graining a Dealbreaker When Buying a Diamond?
Not necessarily. Mild or faint graining has little to no impact on a diamond’s overall beauty, especially if it is only visible under magnification. However, strong graining that affects transparency and brilliance may be a concern.

Always check the grading report and view the diamond in person before purchasing. If you are unsure, consult with a certified gemologist or independent diamond expert for a professional opinion.

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Green Diamond

Green Diamond: A Rare and Unique Natural Treasure

A Rare and Unique Natural Treasure
A green diamond is a diamond that exhibits a natural green body colour, making it one of the rarest and most sought-after coloured diamonds in the world. For a diamond to be classified as a true green diamond, green must be the dominant hue, although it may have secondary modifying tones of yellow, blue, or grey.

These remarkable diamonds owe their distinctive green hue to exposure to natural radiation deep within the Earth’s crust over millions of years. The radiation interacts with the diamond’s atomic structure, creating unique structural defects that result in its green coloration. Because of the highly specific and rare conditions required for their formation, natural green diamonds are exceptionally rare and valuable.

Formation of Natural Green Diamonds
Unlike most coloured diamonds, which owe their colour to trace elements (such as boron in blue diamonds or nitrogen in yellow diamonds), green diamonds derive their colour from natural irradiation.

How it Happens:

Natural Radiation Exposure: Over millions of years, the diamond is exposed to radioactive minerals such as uranium or thorium in the Earth’s crust.
Structural Alterations: The radiation disrupts the arrangement of carbon atoms in the diamond’s crystal lattice, creating a “radiation-induced colour centre.”
Absorption of Light: These defects allow the diamond to absorb red and yellow light, making the diamond appear green to the human eye.
Key Fact: The green colour usually forms on the surface of the rough diamond, which means that careful cutting is required to preserve the colour in the final polished gem.

Shades & Intensity of Green Diamonds
Like all fancy-coloured diamonds, green diamonds are graded based on hue, tone, and saturation. The most valuable green diamonds have a pure green hue with strong saturation. However, many natural green diamonds exhibit secondary modifying tones that affect their final colour.

Green Diamond Colour Classifications:
Colour Name Description Common Secondary Hues
Fancy Light Green Soft, pastel green colour Yellow, Grey
Fancy Green True green with medium saturation Yellow, Blue
Fancy Intense Green Vibrant, rich green hue Blue, Yellow
Fancy Vivid Green Deep, highly saturated green Minimal or No Modifying Tones
Fancy Deep Green Darker green with strong depth Grey, Yellow
The rarest and most valuable green diamonds are those with a strong, pure green hue and minimal secondary modifiers.

Famous Green Diamonds
Due to their rarity, natural green diamonds have become legendary in the world of gemstones. Some of the most famous examples include:

The Dresden Green Diamond (41.00 ct)

One of the most famous and largest natural green diamonds in existence.
Weighing 41.00 carats, it exhibits a pure green colour with exceptional clarity.
Believed to have originated in India, it is now housed in Germany’s Green Vault museum.
The Aurora Green Diamond (5.03 ct)

The largest Fancy Vivid Green diamond ever auctioned.
Sold for $16.8 million at Christie’s in 2016.
The Ocean Dream Diamond (5.51 ct)

A unique blue-green diamond with a distinctive Fancy Deep Blue-Green colour.
Exhibits a combination of radiation exposure and boron content.
The Chopard Green Diamond (10.02 ct)

A Fancy Intense Green diamond set in a ring by Chopard.
One of the most valuable green diamonds in the world.
How Are Green Diamonds Graded?
Green diamonds are graded based on the 4Cs (Carat, Colour, Clarity, and Cut), with special emphasis on colour intensity.

Hue: The primary colour must be green, though modifying hues like yellow, blue, or grey may be present.
Tone: Determines how light or dark the green appears.
Saturation: The strength or intensity of the green hue—more saturated stones are more valuable.

Laboratories like the GIA (Gemological Institute of America) and DCLA (Diamond Certification Laboratory of Australia) provide certificates to verify a green diamond’s natural origin.

Treated vs. Natural Green Diamonds
Because natural green diamonds are incredibly rare, some diamonds undergo treatments to enhance or artificially create a green hue. These treatments include:

Radiation Treatment – Exposing diamonds to artificial radiation to mimic natural colouration.
HPHT (High Pressure, High Temperature) Processing – Alters the internal structure to change colour.
Coating – Applying a thin layer of green material to the diamond’s surface.
Key Buyer’s Tip: Always verify that a green diamond’s colour is natural by requesting a grading report from an independent, recognised gemological laboratory (such as DCLA or GIA).

Are Green Diamonds a Good Investment?
Extreme Rarity – Natural green diamonds are among the rarest coloured diamonds, making them highly desirable.
High Market Demand – Prices for Fancy Vivid Green diamonds have consistently increased over time.
Auction Record Breakers – Green diamonds regularly fetch millions at auctions.

The most valuable green diamonds are Fancy Intense or Fancy Vivid Green with minimal secondary hues and strong saturation.

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Grading Report

Grading Report: The Blueprint of a Diamond's Quality

Grading Report: The Blueprint of a Diamond’s Quality
A grading report, also known as a diamond certificate, is an official document issued by a recognised and independent diamond grading laboratory. It provides a detailed, unbiased assessment of a diamond’s characteristics based on internationally accepted grading standards.

This report plays a critical role in determining a diamond’s quality, authenticity, and market value, allowing buyers, sellers, and investors to make informed decisions.

What is Included in a Diamond Grading Report?
A diamond grading report contains a comprehensive analysis of a diamond’s physical and optical properties. The following elements are typically included:

1. Identification Details
Report Number – A unique serial number assigned to the diamond, used for tracking and verification.
Date of Examination – The date the diamond was graded.
Laboratory Name & Logo – Ensures authenticity and trustworthiness of the certification body (e.g., DCLA, GIA, IGI, HRD).
2. The 4Cs of Diamond Grading
Carat Weight – The diamond’s exact weight, measured to the nearest hundredth of a carat.
Cut Grade – Evaluates the diamond’s proportions, symmetry, and polish, impacting its brilliance and fire.
Colour Grade – Determines how colourless the diamond is, graded on a scale from D (colourless) to Z (light yellow/brown).
Clarity Grade – Assesses internal inclusions and surface blemishes, ranging from Flawless (FL) to Included (I3).
3. Additional Diamond Characteristics
Shape & Cutting Style – Specifies the diamond’s shape (e.g., round, princess, oval) and cut style.
Measurements – Precise dimensions of the diamond, including diameter, table size, and depth.
Girdle Thickness – Evaluates the diamond’s girdle proportion (thin, medium, thick).
Culet Size – Determines if the bottom facet (culet) is pointed, small, or large.
Polish & Symmetry – Rates how well the diamond’s facets are cut and aligned, affecting its sparkle.
Fluorescence – Indicates if the diamond emits a glow under UV light, rated from None to Strong.
4. Diamond Proportions & Light Performance
Proportion Diagram – A detailed illustration showing the diamond’s exact cut proportions.
Light Performance Analysis (in some reports) – Shows how effectively the diamond reflects light.
5. Clarity Characteristics Plot (Inclusion Map)
A diagram indicating the type, location, and size of inclusions or blemishes.
Helps identify the diamond and distinguish it from others.
6. Comments & Additional Features
Any unique observations about the diamond, such as laser inscriptions or special cutting techniques.
7. Security Features & Verification
Some reports contain laser-engraved serial numbers on the girdle for easy identification.
Advanced security features like holograms, QR codes, and online verification portals ensure authenticity.
Grading Report vs. Appraisal: What’s the Difference?
Many people mistakenly believe a grading report and an appraisal are the same, but they serve different purposes:

Feature Grading Report Appraisal
Issued By Independent gemological laboratory (e.g., GIA, DCLA, IGI) Jewellery appraiser or valuation expert
Purpose Determines the diamond’s quality Assigns a monetary value for insurance, resale, or probate
Contains a Value?  No monetary value  Includes an estimated market value
Objectivity Completely unbiased May be influenced by market trends or jeweller pricing
Validity Period Permanent Needs updating over time due to price fluctuations
A diamond grading report is not an appraisal—it does not assign a price to the diamond but provides an objective assessment of its quality and characteristics.

Why is a Grading Report Important?
Ensures Trust & Transparency
Provides a scientific, unbiased evaluation of the diamond’s quality.
Helps prevent fraud or misrepresentation by verifying the diamond’s true attributes.
Helps Determine Market Value
A certified diamond holds more value than an uncertified one.
Allows buyers to compare diamonds based on verified grading standards.
Essential for Insurance & Resale
Insurance companies require a grading report to determine coverage and replacement value.
A report helps sellers accurately price and market their diamond.
Prevents Overpaying
Ensures buyers are not paying for a diamond that does not match its advertised quality.
Helps investors and collectors make informed purchases.
Which Laboratories Issue Grading Reports?
Only independent and reputable gemological laboratories should issue a grading report. Some of the most respected names in the industry include:

DCLA (Diamond Certification Laboratory of Australia) – The official CIBJO laboratory for Australia, known for strict and consistent grading.
GIA (Gemological Institute of America) – One of the most widely recognised authorities in diamond grading.
IGI (International Gemological Institute) – Popular for grading both natural and lab-grown diamonds.
HRD (Hoge Raad voor Diamant, Belgium) – Known for high standards in diamond certification.

Always check the laboratory’s reputation before relying on a grading report, as some lesser-known labs may have looser grading standards.

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Grainer

The term "grainer" is used in the diamond industry to describe a diamond’s weight in quarter-carat (0.25 ct) increments.

A Traditional Unit of Diamond Weight Measurement
The term “grainer” is used in the diamond industry to describe a diamond’s weight in quarter-carat (0.25 ct) increments. It is derived from an ancient method of weighing gemstones and precious materials using natural seeds or grains.

In historical gemstone trading, the weight of diamonds was originally measured in grains of wheat or rice before the adoption of the metric carat system. One carat (1.00 ct) was equivalent to four grains of rice, leading to the term “four grainer” for a 1.00-carat diamond (4 × 0.25 ct = 1.00 ct).

Understanding the Grainer System in Diamond Weight
The grainer system remains a widely used traditional unit in the diamond industry, particularly among traders, jewellers, and manufacturers.

Grainer Diamond Weight (Carats) Description
One Grainer 0.25 ct A small diamond often used in accent stones or cluster settings.
Two Grainer 0.50 ct A half-carat diamond, popular for jewellery.
Three Grainer 0.75 ct A diamond nearing the one-carat mark.
Four Grainer 1.00 ct A full-carat diamond, a benchmark size in the industry.
Eight Grainer 2.00 ct A two-carat diamond, considered a luxury size.
Since carat weight affects the value of a diamond exponentially, rather than linearly, a four grainer (1.00 ct) diamond is worth significantly more than four one-grainer (0.25 ct) diamonds of the same quality.

Historical Origins of the Grainer System
1. Early Trade and Natural Measurement
Before precise gemstone scales, ancient traders used grains of wheat, rice, or carob seeds to determine gemstone weight.
The carob seed was particularly favoured due to its uniform size and weight, eventually leading to the development of the carat system.
2. The Transition to Carats
Over time, the industry standardised the weight of one carat to 200 milligrams (0.200 grams).
The term “grainer” persisted, especially in wholesale diamond trading and manufacturing, as it provided a quick reference for size estimation.
Modern Usage of the Grainer System
1. Wholesale Diamond Trading & Pricing
Grainer terminology is common among diamond dealers, particularly in India, Antwerp, New York, and Hong Kong.
Traders often negotiate diamond prices in terms of grainers rather than carat weight.
2. Diamond Sorting & Manufacturing
In diamond cutting and sorting, rough diamonds are categorised into grainers to estimate how they will be cut into polished stones.
Rough diamonds may be described as one-grainer rough (0.25 ct) or four-grainer rough (1.00 ct), depending on their potential yield.
3. Jewellery Design & Setting
Accent stones in rings, earrings, and bracelets are often measured in grainers rather than carats for precision.
For example, a tennis bracelet may contain 20 two-grainers (0.50 ct each), totalling 10.00 carats.
Why the Grainer System Still Matters Today
Quick Size Reference – Allows jewellers and traders to communicate diamond weights efficiently.
Tradition & Heritage – Preserves historical methods of diamond measurement.
Practical for Diamond Sorting – Helps manufacturers categorise and plan rough diamond cutting.

Although modern diamond transactions primarily use the metric carat, the grainer system remains a valuable industry standard, particularly in wholesale and manufacturing sectors.

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Girdle Thickness

Girdle Thickness: Importance in Diamond Cut & Durability
Girdle thickness refers to the width of the diamond’s girdle, which is the outer edge separating the crown (top) from the pavilion (bottom). It plays a crucial role in the diamond’s durability, setting security, and overall appearance.

A well-proportioned girdle ensures the diamond maintains structural integrity while maximising its face-up size and brilliance. If the girdle is too thin, it becomes prone to chipping, while an excessively thick girdle can add unnecessary carat weight without increasing the visual size.

How Girdle Thickness is Measured
Girdle thickness is usually assessed as a percentage of the average diameter of the diamond. The Gemological Institute of America (GIA) and other major gemological labs describe girdle thickness using standard terms, which range from extremely thin to extremely thick.

GIA Girdle Thickness Grading Scale
Girdle Thickness Description Impact on Durability & Appearance
Extremely Thin Very narrow and difficult to see. High risk of chipping, especially in prong settings.
Thin Slightly more visible but still delicate. Can be durable but may still chip with rough handling.
Medium Well-balanced thickness. Ideal for durability and brilliance.
Slightly Thick A little more pronounced but still proportionate. Generally safe and adds slight weight.
Thick Noticeably wider girdle. Adds weight without significant face-up size increase.
Very Thick A substantial edge, clearly visible. Makes the diamond appear smaller than its carat weight.
Extremely Thick Very broad, often visible from above. Adds excess carat weight with little aesthetic benefit.
How Girdle Thickness Affects a Diamond
1. Durability & Wear Resistance
Too Thin (Extremely Thin or Thin)

Prone to chipping or breaking, especially at points in fancy shapes (e.g., marquise, pear, princess cuts).
Less secure in settings that expose the girdle, such as prong settings.
Too Thick (Very Thick or Extremely Thick)

Reduces the likelihood of damage but adds extra weight to the diamond.
May require deeper prongs or bezel settings, limiting design options.
2. Diamond Size & Spread
A medium to slightly thick girdle allows a diamond to appear larger for its carat weight.
A thick to extremely thick girdle traps weight in the middle of the stone, making it look smaller than other diamonds of the same carat weight.
3. Light Performance & Brilliance
Ideal girdle thickness supports the proper reflection and refraction of light within the diamond.
Overly thick girdles can cause light leakage, reducing brilliance.
Uneven girdles (with varying thickness) can affect symmetry, leading to inconsistencies in sparkle.
Girdle Thickness in Different Diamond Shapes
Some diamond shapes naturally require thicker girdles for durability:

Diamond Shape Recommended Girdle Thickness Reason
Round Brilliant Thin to Slightly Thick Standard cut design maximises brilliance.
Princess Cut Medium to Slightly Thick Sharp corners need extra protection.
Marquise & Pear Slightly Thick to Thick Points are fragile and prone to chipping.
Oval & Cushion Thin to Medium Balanced proportions enhance sparkle.
Emerald & Asscher Medium to Thick Step cuts require sturdier girdles for protection.
Heart Shape Slightly Thick to Thick The cleft and point need reinforcement.
How to Choose the Best Girdle Thickness
Best for Durability: Medium to Slightly Thick (avoids chipping while maintaining beauty).
Best for Appearance & Spread: Thin to Medium (provides a larger face-up look).
Best for Value: Avoid extremely thick girdles that add unnecessary weight.

Always check a diamond’s girdle thickness in its grading report (e.g., GIA, DCLA) before purchasing.

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Gemmology

Gemmology: The Science, Art, and Profession of Evaluating Gemstones

The Science, Art, and Profession of Evaluating Gemstones
Gemmology is the scientific study of gemstones, encompassing their identification, evaluation, grading, and authentication. It is both an art and a science, requiring technical expertise, practical skill, and an eye for beauty. While diamonds are a major focus of gemmology, the field also includes coloured gemstones such as rubies, sapphires, emeralds, and other precious and semi-precious stones.

Key Aspects of Gemmology
1. Scientific Foundation
Gemmology is rooted in the study of crystallography, mineralogy, and optics. Key scientific principles include:

Chemical Composition: Each gemstone has a unique chemical structure; for example, diamonds are composed of pure carbon, while sapphires and rubies are varieties of corundum (Al₂O₃).
Crystal Structure: Gemstones have distinct crystal systems (e.g., cubic for diamonds, hexagonal for sapphires).
Optical Properties: Refraction, dispersion, and birefringence affect a gemstone’s brilliance and colour.
Hardness & Durability: Measured on the Mohs scale, where diamonds rank at 10, making them the hardest natural substance.
2. Identification of Gemstones
A gemmologist’s primary role is to accurately identify gemstones and differentiate natural stones from synthetics or imitations. Methods include:

Microscopic Examination: Identifies inclusions, growth patterns, and treatments.
Refractive Index (RI) Testing: Measures how light bends through a gemstone.
Spectroscopy: Analyses light absorption to determine chemical composition.
UV Fluorescence: Helps distinguish natural from treated or synthetic stones.
Specific Gravity (SG) Testing: Determines gemstone density.
3. Diamond & Gemstone Grading
Gemmologists follow internationally recognised grading systems, such as:

The 4 Cs for Diamonds:
Carat Weight – Size of the diamond.
Cut – Quality of faceting, affecting brilliance.
Colour – Rated from D (colourless) to Z (yellow/brown).
Clarity – Measures internal and external flaws.
Coloured Gemstones Grading:
Hue (basic colour, e.g., blue, green, red).
Tone (lightness or darkness of the colour).
Saturation (intensity and purity of the colour).
4. Treatment & Enhancement Detection
Many gemstones undergo treatments to improve their appearance. A gemmologist must identify enhancements such as:

Heat treatment (common in sapphires and rubies).
Irradiation (used in topaz and diamonds).
Fracture filling (glass-filled rubies or laser-treated diamonds).
5. Synthetic & Imitation Gemstones
With technological advances, synthetic gemstones (lab-created but chemically identical to natural ones) are becoming more prevalent. Some methods used in synthetic diamond production include:

HPHT (High Pressure High Temperature)
CVD (Chemical Vapour Deposition)
A gemmologist must distinguish these from natural diamonds using advanced spectroscopy, UV fluorescence, and growth pattern analysis.

The Role of a Professional Gemmologist
Gemmologists work in various fields, including:

Jewellery Industry: Evaluating gemstones for jewellery design and valuation.
Laboratories & Certification: Providing official grading reports (e.g., GIA, DCLA).
Auction Houses & Appraisal: Valuing gemstones for resale, investment, or insurance purposes.
Mining & Sourcing: Identifying raw gemstones at the source.
Education & Research: Advancing the field through scientific studies.

Gemmology is a multifaceted discipline that blends science, artistry, and expertise to assess and value gemstones. As the industry evolves, with increasing synthetic production and new treatment methods, the role of a skilled gemmologist remains vital in ensuring the integrity of the gemstone market.

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Girdle

The girdle helps protect the diamond from chipping and damage, particularly along its edges.

Functions of the Girdle
Structural Protection

The girdle helps protect the diamond from chipping and damage, particularly along its edges.
A properly proportioned girdle ensures the diamond remains stable when set in a ring, pendant, or other jewellery.
Facilitation of Setting

The girdle provides a secure surface for jewellers to grasp and set the diamond in different types of mounts, such as prong, bezel, or tension settings.
A girdle that is too thin can be fragile, while an excessively thick girdle can add unnecessary weight without enhancing the stone’s beauty.
Influence on Light Performance

While the girdle itself does not directly affect a diamond’s brilliance, an extremely thick girdle can trap light, reducing overall sparkle.
A well-proportioned girdle complements the diamond’s cut and symmetry, contributing to optimal light reflection and refraction.
Types of Girdle Finishes
The girdle of a diamond can be finished in different ways, affecting both appearance and durability:

Faceted Girdle

The most common finish in modern diamonds.
Consists of small, polished facets around the circumference, improving light reflection and enhancing the stone’s overall appearance.
Often seen in round brilliant and fancy-cut diamonds.
Polished Girdle

A smooth, glass-like girdle with no visible facets.
Often used in high-quality diamonds to create a seamless transition between the crown and pavilion.
Provides a sleek, elegant look but does not enhance brilliance.
Bruted Girdle (Rough Girdle)

A frosted or slightly grainy appearance, common in older diamond cuts such as the Old European and Old Mine cuts.
This finish results from the traditional bruting process, where diamonds are shaped against each other to form a round outline.
Less common in modern diamonds but still seen in vintage jewellery.
Girdle Thickness and Its Importance
Girdle thickness varies from extremely thin to extremely thick, and this measurement impacts both durability and appearance. The GIA (Gemological Institute of America) and other grading labs assess girdle thickness using terms such as:

Girdle Thickness Description Potential Issues
Extremely Thin Very fine edge, barely visible. Prone to chipping, especially in prong settings.
Thin Visible but delicate. Can still be fragile in daily wear.
Medium Ideal thickness for durability and aesthetics. No major concerns.
Slightly Thick Adds slight weight to the diamond but remains secure. No major concerns.
Thick to Extremely Thick Very pronounced edge. Adds unnecessary weight without increasing face-up size, reducing value.
Key Considerations:
Ideal Range: A medium to slightly thick girdle is generally preferred for durability without adding unnecessary weight.
Fancy Cuts: Certain fancy-cut diamonds (e.g., marquise, pear, heart) often have thicker girdles to reinforce delicate points.
Avoiding Chipping: Very thin girdles can be risky, especially in high-contact jewellery like engagement rings.
Impact of the Girdle on Carat Weight
The girdle affects a diamond’s spread (face-up size) and carat weight:

A thicker girdle can add to the carat weight without making the diamond appear larger.
An overly thick girdle may result in a smaller apparent size, as more weight is concentrated in the middle rather than the top view.
A thin or medium girdle maximises the face-up appearance of the diamond.
For buyers, this means that a poorly proportioned girdle can lead to paying for extra carat weight that does not translate to visible size.

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Gem Quality

Only about 20% of mined diamonds are of gem quality, meaning they meet the necessary standards for use in jewellery. The remaining 80% fall into the industrial-grade category, used in various commercial and technological applications. Let’s explore this in more detail:

Breakdown of Diamond Quality
Gem-Quality Diamonds (≈20%)

These diamonds are characterised by high clarity, colour, and cut quality, making them desirable for jewellery.
They undergo cutting and polishing to enhance their brilliance before being set in rings, necklaces, earrings, and other fine jewellery.
Their value depends on the 4 Cs (Carat, Cut, Colour, Clarity) and whether they are natural or treated.
Industrial-Grade Diamonds (≈80%)

These diamonds are lower in clarity, may have visible inclusions, and often exhibit yellow, brown, or grey colours that make them unsuitable for jewellery.
They are used in industries due to their hardness and durability, which are essential for cutting, drilling, grinding, and polishing applications.
Common uses include:
Diamond-tipped drill bits and saw blades for construction and mining.
Abrasive powders for polishing and grinding metals.
High-tech applications, such as semiconductors and heat conductors in electronics.
Why the Low Percentage of Gem-Quality Diamonds?
Several factors contribute to why only a small fraction of mined diamonds qualify as gem-grade:

Formation Conditions: Natural diamonds form under extreme pressure and temperature deep within the Earth’s mantle. Impurities or irregular growth can affect their clarity, colour, or shape.
Inclusions and Blemishes: Many diamonds contain internal inclusions (tiny fractures or foreign minerals) and external blemishes, making them less suitable for jewellery.
Colour and Transparency: Gem-quality diamonds are typically colourless to light yellow (D-Z on the GIA colour scale). Many mined diamonds have a strong brown or grey tint, reducing their desirability.
Cutting Yield: Some rough diamonds, even if of good quality, may be inefficiently shaped for cutting into marketable gemstones.
Impact on the Diamond Market
Rarity Drives Value: Since high-quality diamonds are less common, they retain their value better than industrial-grade diamonds.
Lab-Grown Diamonds: The gap in supply between industrial and gem-quality diamonds has led to advancements in lab-grown diamonds, which can be produced with high clarity and controlled quality.
Recycling & Recutting: Some lower-quality diamonds can be recut or treated (e.g., laser drilling, fracture filling) to enhance their appearance, but these diamonds are usually less valuable than untreated stones.

The fact that only 1 in 5 mined diamonds meets gem-quality standards highlights the rarity and value of fine diamonds. This also influences pricing, sourcing strategies, and market trends, as both natural and lab-grown diamonds compete in the luxury and industrial sectors.