Diamonds – Page 60 – The Diamond Certification Laboratory of Australia (DCLA)

July, 2017February, 2025

Natural

A natural refers to a portion of the original rough diamond’s outer surface that remains unpolished on a finished, faceted diamond. This feature is intentionally left on the stone during the cutting and polishing process and is typically found along the girdle—the outer edge of the diamond that separates the crown (top) from the pavilion (bottom).

Why Are Naturals Left on a Diamond?
Maximizing Carat Weight

Diamond cutters aim to retain as much of the rough stone as possible. Removing all natural surfaces may require excessive cutting, reducing the final carat weight of the polished diamond.
Preserving Crystal Integrity

Some rough diamonds have growth lines or inclusions that, if cut away, could weaken the stone or impact its durability. Leaving a natural in a strategic area helps maintain the diamond’s overall strength.
Minimizing Waste

Since natural diamonds are rare and valuable, preserving part of the rough minimizes unnecessary loss of material during cutting.
Proof of Natural Origin

In some cases, gemologists and collectors appreciate naturals as evidence that the diamond was cut from a genuine rough stone rather than being lab-grown or heavily altered.
Impact on a Diamond’s Appearance and Quality
Polish Grade:

Naturals are considered minor surface features and are factored into the polish grade of a diamond. A diamond with significant naturals may receive a lower polish grade from gemological laboratories like DCLA, GIA, or AGS.
Location Matters:

If confined to the girdle area, naturals do not significantly affect the diamond’s overall appearance, brilliance, or value.
If present on the crown or table (top facets), they may be more visible and could impact the diamond’s aesthetic appeal.
Girdle Thickness Considerations:

Some naturals can contribute to an uneven girdle thickness, which might affect durability. A very thin girdle with a natural could increase the risk of chipping.
How to Identify a Natural in a Diamond?
Visible under Magnification
Naturals are typically small, textured, and may appear frosty or grainy under a jeweler’s loupe (10x magnification) or a microscope.
GIA & DCLA Reports
If a diamond has a natural, it is often noted in the grading report, usually under the clarity characteristics or polish comments section.
Naturals vs. Other Surface Features
Natural vs. Extra Facet:
A natural is an original rough diamond surface left untouched, while an extra facet is a man-made additional cut that is not part of the standard faceting pattern.
Natural vs. Cavity:
A natural is a minor surface remnant, whereas a cavity is an indentation or deeper surface flaw that can affect durability.
Are Naturals a Flaw?
Not necessarily. If located on the girdle, naturals are generally not a concern for beauty or durability. They do not impact the diamond’s brilliance or fire, and they are considered an acceptable feature in diamond cutting, especially for maximizing weight retention.

However, if a natural extends beyond the girdle onto visible facets, it could slightly affect the stone’s appearance and might be more noticeable.

July, 2017February, 2025

Milky Diamond

A milky diamond refers to a gemstone that exhibits a cloudy or hazy appearance, which results in reduced transparency, brilliance, and overall life of the stone. This milky effect can significantly affect the diamond’s visual appeal, as it diminishes the stone’s ability to reflect light and sparkle. The term “milky” is used to describe diamonds that appear opaque or have a frosted, white haze that can obscure the clarity and sparkle of the diamond.

There are several factors that can contribute to a diamond being described as milky:

Cloudy Inclusions: The most common cause of a milky appearance is the presence of dense, white, or opaque inclusions inside the diamond, known as “clouds.” These inclusions scatter light within the stone, making it appear hazy and reducing its brilliance. Clouds are generally made up of tiny crystals of minerals or gas bubbles trapped inside the diamond during its formation. While small clouds may have little effect on the diamond’s appearance, dense or large clouds can result in a noticeable milky effect.

Strong Fluorescence: Another factor that can cause a diamond to appear milky is intense fluorescence. Fluorescence refers to the emission of a visible light when the diamond is exposed to ultraviolet (UV) light. Diamonds that exhibit strong fluorescence, particularly blue fluorescence, may appear milky or hazy under certain lighting conditions, especially in daylight or under UV light. In some cases, strong fluorescence can create a visible bluish cloudiness in the diamond’s appearance, leading to a milky look.

Grading of Transparency: The DCLA (Diamond Certification Laboratory of Australia) uses a specific grading system to evaluate diamonds based on factors such as clarity, cut, colour, and transparency. When it comes to transparency, the DCLA assesses the diamond’s ability to transmit light and its overall visual quality. A milky diamond will generally receive a lower transparency grade due to the diminished light return caused by internal inclusions, fluorescence, or other optical issues. A diamond with a reduced transparency grade will appear less vibrant and lifeless compared to a perfectly clear stone.

Other Factors: In addition to inclusions and fluorescence, the clarity and overall quality of the diamond’s cut can also influence the diamond’s transparency. A poorly cut diamond, or one with irregularities in the facets, can exacerbate the milky effect by causing light to be scattered in a way that reduces its brilliance.

Impact on Value:
Milky diamonds tend to have a lower value compared to clear diamonds because their reduced transparency results in a diminished visual appeal. The milky effect makes them less desirable for high-end jewelry, where brilliance and clarity are highly valued. However, depending on the severity of the milky appearance, some buyers may still find these diamonds attractive for specific designs or purposes, such as lower-cost pieces or designs that mask the effect with intricate settings.

DCLA Transparency Grade:
When diamonds are certified by the DCLA, one of the factors considered is the diamond’s transparency. The transparency grade of a diamond can be influenced by a variety of internal and external factors. A milky diamond, due to its hazy or cloudy appearance, would likely receive a lower transparency grade, indicating that it does not possess the ideal light return and brilliance expected from a high-quality diamond. The DCLA’s grading system provides an objective way to assess these characteristics, allowing buyers and sellers to make informed decisions about the diamond’s quality and value.

July, 2017February, 2025

Mohs Scale

The Mohs Scale of Hardness is a qualitative scale that ranks minerals based on their ability to resist scratching. Developed by German mineralogist Friedrich Mohs in 1812, the scale is widely used in geology, gemology, and material science to compare the hardness of different minerals and gemstones. It ranges from 1 (softest) to 10 (hardest), with each mineral capable of scratching those ranked below it while being scratched by those ranked above it.

Mohs Scale of Hardness – Ranking of Minerals
Mohs Hardness Mineral Common Comparison
1 Talc Very soft; can be scratched by a fingernail; found in talcum powder.
2 Gypsum Soft; can be scratched by a fingernail; used in plaster and drywall.
3 Calcite Can be scratched by a copper coin; found in limestone and chalk.
4 Fluorite Can be scratched by a knife blade; used in fluorine production.
5 Apatite Can be scratched by a steel nail; found in teeth and bones.
6 Orthoclase Feldspar Harder than glass; a common mineral in granite.
7 Quartz Can scratch glass and steel; commonly found in sand and gemstones like amethyst and citrine.
8 Topaz A durable gemstone; harder than quartz and feldspar.
9 Corundum Includes sapphires and rubies; extremely hard, only scratched by diamond.
10 Diamond The hardest naturally occurring substance; used in cutting tools and jewelry.
Understanding the Mohs Scale
The Mohs scale is ordinal, meaning the difference in hardness between minerals is not proportional. For example, diamond (10) is about four times harder than corundum (9), even though the scale suggests a difference of only one unit.
Some synthetic materials and alloys can exceed the hardness of natural minerals. For example, tungsten carbide and cubic boron nitride have hardness levels approaching that of diamond.
While hardness measures scratch resistance, it does not indicate a mineral’s toughness or resistance to breaking. Diamond, while the hardest mineral, is brittle and can be shattered by a sharp blow.
Mohs Scale and Gemology
In gemology, the Mohs scale helps determine the durability of gemstones for everyday wear. Harder stones (e.g., diamond, sapphire, ruby) are ideal for engagement rings and jewelry exposed to frequent wear, while softer stones (e.g., opal, pearl, turquoise) require extra care to avoid scratches.

July, 2017February, 2025

Melee

Melee diamonds are small, polished diamonds that typically weigh less than 15 points (0.15 carats) each. These diamonds are often used in settings where multiple stones are grouped together to create a brilliant and dense appearance of sparkle, especially in intricate jewelry designs such as pavé, halo, and channel settings.

The word “melee” comes from the French term mêlée, which means “a conflict” or “a jumble.” In the context of diamonds, it refers to the arrangement of small stones, often set in close proximity, to achieve a cohesive and eye-catching visual effect.

Despite their smaller size, melee diamonds can still offer high clarity and quality, depending on the individual stone’s cut, colour, and clarity. They are typically graded collectively, meaning that instead of each stone being individually assessed for its qualities, the melee as a whole is evaluated for its overall consistency and aesthetic appeal. This makes melee diamonds more affordable compared to larger stones, while still offering considerable brilliance and impact when used in larger jewelry designs.

Melee diamonds are especially popular in engagement rings, wedding bands, and earrings, where they complement a larger center diamond or gemstone. Due to their smaller size, they are generally used to accentuate the design, offering added sparkle without taking attention away from the central feature of the piece. Moreover, the intricate settings often used to hold melee diamonds can increase the overall value of a piece by adding complexity and refinement to its craftsmanship.

Because of their relatively small size, melee diamonds are often sold in bulk or pre-set into jewelry, and they are sometimes categorized by weight groups, such as “single cut” or “full cut” melee diamonds, each with its own level of precision in cutting. They are frequently sourced from diamond wholesalers or dealers who specialize in smaller stones, and they can be a cost-effective option for those looking to add diamond accents to their jewelry collections.

Individual melee diamonds may not carry the same weight or monetary value as larger stones, their combined effect can create stunning jewelry pieces that are both beautiful and economically accessible.

July, 2017February, 2025

Marquise Cut

The marquise cut is a diamond shape that is elongated and features two pointed ends, creating an elegant, oval-like shape. This cut is named after the Marquise de Pompadour, the mistress of King Louis XV of France, who is said to have commissioned a diamond in this shape to resemble the smile of the Marquise. The shape is often associated with royalty and sophistication, as it combines beauty with a sense of regal charm.

Also known as a navette (which is the French term for “little boat”), the marquise cut’s design is reminiscent of a boat’s hull, with its long, sweeping lines and pointed ends. This cut is distinctive and versatile, often used in rings, earrings, and necklaces to create a striking and elongated visual effect.

Characteristics of a Marquise Cut
Shape and Proportions:

The marquise cut is an elongated oval with pointed tips at both ends, giving it a symmetrical and graceful appearance. The length-to-width ratio can vary, but it is typically quite long and narrow, which enhances the illusion of a larger size.
The length of the diamond can range from about 1.5 to 2.5 times its width, and the exact ratio depends on the preference of the buyer or the designer. A diamond with a more elongated shape will often appear larger than a round diamond of the same carat weight.
Brilliance and Sparkle:

The marquise cut is designed to maximise the diamond’s brilliance, meaning it reflects a high degree of light, resulting in an eye-catching, sparkly appearance. This is due to the number of facets that are carefully aligned to reflect light in the optimal manner.
The elongated shape enhances the visual size of the diamond, making it look larger than a round brilliant cut of the same weight. It also offers the added benefit of a larger surface area to show off the diamond’s brilliance.
Facets and Cut:

The marquise cut is usually faceted similarly to a round brilliant diamond, with 58 facets that maximise light reflection. The crown of the diamond, or the top part, has a series of triangular and kite-shaped facets, which work together to create the sparkle.
Due to the pointed ends, it is important for the cutter to ensure that these areas are not too sharp, as they can make the diamond more susceptible to damage. The cutting process focuses on maintaining the integrity of the shape and ensuring that the facets are aligned to produce the maximum brilliance and fire.
Unique Design and Versatility:

The marquise cut’s distinctive elongated form makes it a popular choice for engagement rings, especially when the goal is to make the diamond appear larger. Its shape is particularly flattering for smaller fingers, as it creates the illusion of length and elegance.
The marquise cut is also versatile in its use in jewellery design, as it pairs well with both traditional and modern settings. It can be used in rings, pendants, earrings, and bracelets, and it is often surrounded by other diamonds or gemstones to enhance its overall appearance.
Visual Appeal:

The elongated silhouette of a marquise cut diamond offers a slimming effect on the finger or the wearer’s appearance, making it a popular choice for those who want to emphasise elegance and sophistication. The cut also provides optical illusions, making the stone appear larger and more slender.
The pointed ends, in particular, create a dramatic and bold look, making marquise diamonds stand out in jewellery pieces. This cut is often chosen by those who want a distinctive, eye-catching piece that is unique and memorable.
Considerations When Choosing a Marquise Cut
Proportions and Symmetry:

When selecting a marquise cut diamond, the proportions and symmetry of the shape are essential. An asymmetrical or improperly proportioned marquise cut can result in a less desirable appearance. For example, a diamond that is too elongated or too broad might not offer the same balance and beauty as one with ideal proportions.
Symmetry is particularly important with the marquise cut, as uneven points or misaligned facets can detract from the overall sparkle and visual appeal.
Length-to-Width Ratio:

As mentioned, the length-to-width ratio is a key consideration for a marquise cut diamond. A ratio that is too extreme (e.g., overly long and narrow) may appear out of proportion, while a more balanced ratio (typically around 1.5 to 2.0) will provide a more harmonious and aesthetically pleasing appearance.
Pointed Ends:

The pointed ends of the marquise cut are vulnerable to damage, such as chipping, if the diamond is not set properly or if it is subjected to physical stress. For this reason, many buyers opt for a protective setting that shields the points. A bezel setting or a setting with raised prongs can help protect these vulnerable areas.
Clarity Considerations:

The clarity of a marquise cut diamond is particularly important because inclusions that appear near the pointed ends can be more noticeable due to the way light interacts with the shape. When purchasing a marquise cut diamond, it’s wise to choose one with minimal inclusions near the tips, as these can be more visible and detract from the diamond’s brilliance.
Popularity and History of the Marquise Cut
The marquise cut has remained a popular choice for engagement rings and jewellery designs for centuries. Its timeless appeal is linked to its association with royalty, particularly after it was named after the French Marquise de Pompadour. The shape has been embraced in various forms of luxury jewellery, and its sleek, sophisticated design continues to attract those seeking a distinctive, elegant piece.

The marquise cut is also a symbol of individuality, offering a unique alternative to traditional round brilliant or cushion-cut diamonds. It provides an option for those who want a ring or piece of jewellery that stands out, while still showcasing the brilliant qualities of the diamond.

July, 2017February, 2025

Lower-Girdle Facets

The lower-girdle facets are crucial elements in the overall symmetry and brilliance of a diamond. These triangle-shaped facets are located on the pavilion of the diamond, directly adjacent to the girdle, which is the outer edge of the diamond. The pavilion refers to the bottom part of the diamond, below the girdle, which is responsible for reflecting light back through the crown and into the observer’s eye.

Position and Structure
Location: The lower-girdle facets are positioned on the pavilion of the diamond, near the girdle. They are situated just below the main facets of the pavilion, including the main pavilion facets, which are the large, flat surfaces that reflect light into the crown.

Shape: These facets are typically triangle-shaped, although their size and exact proportions can vary depending on the cut of the diamond. In some diamonds, these lower-girdle facets may be slightly elongated or modified, but they usually maintain a triangular form.

Function: The primary function of the lower-girdle facets is to help direct light in the diamond, contributing to its brilliance and scintillation. These facets work by reflecting light that enters the pavilion from below, which then bounces back through the crown of the diamond, creating the visual effects that make diamonds sparkle. The interaction between the light and these facets is essential in maximizing the diamond’s overall visual appeal.

Impact on Diamond Performance
Brilliance:

The brilliance of a diamond is its ability to reflect white light. The lower-girdle facets play an important role in this by directing light from the pavilion back into the crown. When the light is properly reflected, it bounces back to the viewer’s eye, enhancing the diamond’s brightness.
Scintillation:

Scintillation refers to the flashes of light that occur when a diamond moves or is viewed from different angles. The lower-girdle facets help enhance scintillation by creating additional reflections and refractions of light. Their triangular shape and position allow them to catch light from various angles, contributing to the diamond’s overall sparkle.
Symmetry:

Properly aligned and symmetrical lower-girdle facets are essential to the overall symmetry of the diamond. When the facets are evenly proportioned, the diamond will have a more visually appealing appearance, with well-defined light reflections and a balanced sparkle. Any irregularities in the alignment or shape of these facets can lead to an uneven distribution of light, reducing the diamond’s brilliance.
Grading the Lower-Girdle Facets
In diamond grading, the quality of the lower-girdle facets is considered as part of the overall cut grade, which evaluates how well the diamond has been shaped and proportioned to maximize its brilliance, fire, and scintillation. Some of the factors that affect the grading of the lower-girdle facets include:

Size and Proportion:

The size and proportion of the lower-girdle facets should be well balanced with the other facets of the diamond, including the main pavilion facets and the upper girdle facets. Proper proportions contribute to the diamond’s overall symmetry and visual appeal.
Symmetry:

Symmetry is one of the key components of diamond grading. Lower-girdle facets should be symmetrical, with uniform size and placement. Any misalignment or uneven facet sizes can disrupt the flow of light through the diamond and impact its overall performance.
Polish:

A well-polished surface on the lower-girdle facets enhances the diamond’s ability to reflect light. Poor polishing can lead to a dull appearance and reduce the brilliance of the diamond.
Role in Different Diamond Cuts
While lower-girdle facets are typically found in round brilliant cut diamonds, their placement and function can also be seen in other shapes that share similar cutting structures. However, the round brilliant cut diamond relies most heavily on the lower-girdle facets to achieve optimal light performance.

Round Brilliant Cut:

In the round brilliant cut, the lower-girdle facets are particularly important in creating the characteristic sparkle and fire that this cut is known for. The precise arrangement of these facets ensures that the diamond exhibits maximum brilliance and scintillation.
Other Fancy Cuts:

While fancy shapes like emerald, princess, or asscher cuts have different facet structures, they still rely on the principles of light reflection and refraction that are found in the lower-girdle facets of the round brilliant cut. For these shapes, the positioning and number of lower-girdle facets can vary, but their purpose remains the same: to enhance the diamond’s brilliance.
Impact of the Lower-Girdle Facets on Diamond Value
Diamonds with well-proportioned and well-cut lower-girdle facets typically have better light performance, meaning they will display more brilliance, scintillation, and fire. As such, diamonds with ideal or well-graded lower-girdle facets are generally considered more valuable because they are more visually appealing. Poorly proportioned or poorly cut lower-girdle facets can negatively affect the diamond’s performance, reducing its overall desirability and value.

July, 2017February, 2025

Life

Life in a diamond refers to the vivid, dynamic quality that gives the diamond its captivating brilliance, dispersion, and scintillation. It is the essence of what makes a diamond sparkle and appear alive under different lighting conditions. While many factors contribute to the overall aesthetic of a diamond, the concept of “life” encompasses how the diamond interacts with light, its ability to reflect and refract light, and the visual impact it has on the viewer.

Key Components of Life in a Diamond
The term “life” is a combination of three key optical phenomena that work together to create the diamond’s stunning visual effects. These include brilliance, dispersion, and scintillation:

Brilliance:

Brilliance refers to the amount of white light that is reflected from the surface and the facets of a diamond. It is a measure of how much light is returned to the viewer’s eye, creating a sparkling, bright effect.
The quality of brilliance depends heavily on the cut of the diamond. Well-cut diamonds with optimal proportions and angles will exhibit the maximum amount of brilliance. When a diamond is cut properly, the light entering through the top is reflected back through the table and facets, creating an intense, white sparkle.
Dispersion:

Dispersion, also known as “fire,” is the effect that occurs when light is split into its constituent colours as it passes through the diamond. This creates the colourful flashes of light that you often see in high-quality diamonds, particularly in sunlight or bright lighting.
The greater the dispersion, the more the diamond will show a rainbow of colours, enhancing its visual beauty. A well-cut diamond will maximise the effect of dispersion, allowing it to reflect the full spectrum of visible light.
Scintillation:

Scintillation refers to the flashes of light and sparkle that appear as the diamond moves. These flashes are the result of light being reflected off the facets of the diamond as it is tilted or rotated.
The more facets a diamond has, and the better its proportions, the greater the scintillation effect. A diamond with excellent scintillation will have a lively, dynamic sparkle, even when viewed from different angles or when moved slightly.
The Role of Cut in Life
The cut of a diamond is the most significant factor influencing its life. The cut determines how well a diamond interacts with light, affecting its brilliance, dispersion, and scintillation. An ideal cut maximises all of these attributes by ensuring that light enters, reflects, and exits the diamond in the most efficient manner possible.

Proportions and Symmetry: Proper proportions and symmetry are critical in the cut of the diamond. A well-cut diamond ensures that the angles of the facets are aligned in such a way that light is properly reflected and refracted, leading to maximum brilliance and fire.

Polish: The quality of the diamond’s polish also impacts its life. A poorly polished diamond may have rough surfaces that cause light to scatter unevenly, reducing brilliance and fire. On the other hand, a well-polished diamond will allow light to enter and exit smoothly, enhancing its sparkle.

Why Life Matters in a Diamond
Visual Appeal: The “life” of a diamond is what attracts the eye and creates the allure that diamonds are known for. The more vibrant and sparkling a diamond appears, the more attractive it will be to the observer. Life adds depth and dimension to the diamond, making it look stunning from all angles.

Value: A diamond with excellent life is often more valuable because it is more visually striking. Diamonds that display higher levels of brilliance, dispersion, and scintillation tend to be more desirable, thus commanding higher prices in the market.

Emotional Impact: A diamond’s life can evoke emotions, especially when it is worn in jewellery such as engagement rings or necklaces. The way a diamond sparkles and shifts with the light can symbolise significant moments or memories, making the emotional value of the stone even greater.

Evaluating Life in a Diamond
When purchasing or evaluating a diamond, the life is an essential consideration. However, unlike colour, clarity, and carat weight, “life” is a more subjective aspect of the diamond. It is not usually quantified on a grading scale, but instead evaluated based on its visual impact.

Lighting Conditions: The effect of life can vary depending on the lighting environment. A diamond might look stunning in natural sunlight, but may appear less lively under low or artificial lighting. For this reason, it’s important to view diamonds in different lighting conditions to fully appreciate their brilliance and fire.

Personal Preference: Life in a diamond can also be subjective based on individual preferences. Some people prefer a diamond with a more intense sparkle, while others may appreciate a subtler effect. Different cuts, such as round brilliant or cushion cut, will exhibit life in unique ways.

Life in the Diamond Industry
Marketing and Presentation: In the diamond industry, life plays a significant role in marketing. Diamonds with exceptional brilliance and sparkle are often highlighted as being “extraordinarily lively,” creating a sense of awe and desire among potential buyers. This makes life an important selling point in the jewellery market.

Technology and Innovations: Advances in cutting technology have greatly improved the life of diamonds. Modern cutting machines allow for greater precision in shaping diamonds, leading to cuts that maximise light reflection and enhance the diamond’s overall beauty. Additionally, the use of advanced techniques such as laser cutting ensures that diamonds have more symmetrical and finely polished facets, resulting in a greater display of life.

July, 2017February, 2025

Loose Diamond

A loose diamond refers to a diamond that is not yet set in any type of jewellery. It is an unmounted stone that remains free, allowing for a more detailed assessment of its qualities before it is placed into a setting such as a ring, necklace, or bracelet. This freedom provides several benefits, including a clearer understanding of the diamond’s characteristics and the flexibility for buyers to choose their preferred mounting.

Importance of Loose Diamonds in the Jewellery Industry
Accurate Evaluation:

When a diamond is loose, its attributes—such as its cut, colour, clarity, and carat weight (the Four Cs)—can be accurately assessed. The diamond is viewed from all angles, and precise measurements can be made. This allows for a thorough and precise evaluation, which is impossible when the diamond is set in jewellery, as the setting may obscure parts of the stone.
Grading labs, such as the Gemological Institute of America (GIA) or the Diamond Certification Laboratory of Australia (DCLA), require diamonds to be loose for accurate certification. When a diamond is mounted, it may be challenging to fully assess certain characteristics, especially clarity, as inclusions might be hidden by the setting.
Better Market Transparency:

Loose diamonds provide greater transparency in the marketplace. Buyers can inspect and compare the characteristics of different diamonds in their natural state. This also allows for greater flexibility in selecting the right stone for a specific piece of jewellery, as customers have the option to customise the setting later based on the loose diamond’s shape and size.
Advantages of Purchasing a Loose Diamond
Customisation:

Purchasing a loose diamond allows the buyer to have full control over the design of their jewellery. Whether it’s for an engagement ring, a pendant, or earrings, customers can choose the setting that best complements their diamond, resulting in a more personalised and unique piece of jewellery.
Loose diamonds also provide the opportunity to create bespoke designs, as they are not restricted to pre-existing settings. Buyers can work with a jeweller to design something that reflects their personal style and preferences.
Cost Efficiency:

A loose diamond may be more affordable than a pre-set diamond in a piece of jewellery, as you are only paying for the stone itself without the cost of the setting. Additionally, buying loose allows buyers to explore different pricing options, including different grading and certification levels, without paying for an expensive mount.
The cost of setting a loose diamond is a separate consideration, but in many cases, the buyer may save on the mounting compared to purchasing an already mounted diamond.
Greater Selection:

Buying a loose diamond offers a wider selection of stones. You are not limited to the diamonds that are already set in jewellery, which may not fit your preferences in terms of quality, shape, or size. Loose diamonds give access to a broader variety of shapes (round, princess, oval, emerald, etc.), sizes, and grades, allowing you to choose a diamond that best suits your needs.
Investment Potential:

Loose diamonds are also popular with investors. They are portable, can be easily stored, and often maintain or increase their value over time, especially high-quality diamonds with favourable characteristics. As the diamond market continues to evolve, loose diamonds provide the flexibility to resell or trade them more easily compared to mounted diamonds.
Challenges of Loose Diamonds
Vulnerability to Damage:

While being unmounted offers several benefits, it also leaves the diamond more exposed to damage. Without a setting to protect it, a loose diamond can be scratched, chipped, or lost more easily. Buyers should take extra care when handling and storing loose diamonds to avoid accidental damage.
Secure packaging and proper storage are critical to maintain the diamond’s condition.
Setting Delays:

After purchasing a loose diamond, the buyer may face delays in having the stone set into their chosen jewellery. The setting process can take time, especially if custom work is involved, and the jewellery itself may not be ready for immediate wear.
It is important to account for the time it takes to create the jewellery around the diamond, which may affect when the customer can actually wear or present the piece.
Loose Diamond Certification
Loose diamonds are typically certified by independent gemological laboratories. This certification ensures that the diamond has been graded and evaluated according to universally recognised standards. The Four Cs (cut, colour, clarity, and carat weight) are the main criteria used to assess the quality of a diamond.

Cut: The diamond’s proportions, symmetry, and polish. This affects how well the diamond reflects light, influencing its brilliance and overall appearance.
Colour: The lack of colour in the diamond. Diamonds are graded on a scale from D (colourless) to Z (light yellow or brown).
Clarity: The presence of internal or external flaws, called inclusions and blemishes. The fewer the imperfections, the higher the clarity grade.
Carat Weight: The weight of the diamond, with one carat equalling 200 milligrams. Larger diamonds are rarer and typically more valuable.
Certification provides reassurance to buyers that the diamond meets certain standards and helps them understand its true value. The report usually includes a diagram of the diamond’s inclusions and any other notable features, which are critical for understanding its characteristics.

Where to Buy Loose Diamonds
Loose diamonds can be purchased from a variety of sources:

Jewellers and Diamond Retailers: Many well-established jewellers offer loose diamonds for sale. Some may also have diamond grading reports available for each stone, giving buyers more confidence in their purchase.

Online Platforms: Online marketplaces and diamond retailers provide access to a large selection of loose diamonds, often with detailed information about each stone’s grading and certification. Some platforms even allow buyers to filter diamonds based on specific criteria, such as carat weight, cut quality, and colour.

Diamond Auctions: For collectors and investors, diamonds can also be found at diamond auctions, where high-quality loose diamonds are sold to the highest bidder.

July, 2017February, 2025

Knot

A knot is a specific type of inclusion found within diamonds. It refers to an included crystal or foreign material that is embedded within the diamond, and in certain cases, it extends all the way to the surface of the stone, disrupting the clarity of the diamond. The knot can sometimes result in a visible raised or burnt area on the diamond’s surface, which may affect both the diamond’s appearance and its overall value.

Formation and Characteristics of a Knot
A knot is formed when a crystal or a foreign material becomes trapped within the diamond during its crystallization process. These inclusions are often caused by other minerals, such as garnet, graphite, or pyrite, which can become incorporated into the diamond’s crystal structure as it forms deep within the Earth’s mantle. These inclusions, when they grow to a size large enough and reach the surface of the diamond, are identified as knots.

The key characteristics of a knot include:

Size: Knots can vary in size, but they are generally larger than many other types of inclusions.
Shape: A knot is often irregularly shaped, with rough edges that can be visible within the diamond.
Visibility: When a knot reaches the surface, it may be visible to the naked eye or under magnification, depending on its size and location.
Effect of a Knot on Diamond Clarity
Inclusions, including knots, are important factors in determining the clarity grade of a diamond. The presence of a knot can significantly reduce a diamond’s clarity, depending on its size, location, and visibility. Since clarity is one of the key factors in diamond grading, knots are generally considered undesirable, especially if they are prominent or affect the overall appearance of the diamond.

The primary impacts of a knot on clarity are:

Lower Clarity Grade: Knots are typically graded as part of the diamond’s clarity assessment. A diamond with a visible knot on the surface may be downgraded in clarity compared to a similar diamond with fewer inclusions or no knots.
Potential for Weakening the Diamond: While knots do not always affect a diamond’s durability, they can sometimes create weak points. If a knot is close to the surface, it may potentially make the diamond more susceptible to damage, such as chipping or cracking.
Visual Appearance of a Knot
When a knot breaks through the surface of the diamond, it can sometimes leave a visible mark, which could be a slightly raised area or a burnt-looking spot. These marks can appear darker or different in texture than the surrounding surface of the diamond. In some cases, knots may appear as small, black or dark spots, particularly if the included crystal is dark or opaque.

Since the surface of a diamond is a key aspect of its overall appearance, the presence of a knot can have an impact on how light interacts with the stone, potentially reducing its brilliance or sparkle. However, in some cases, the knot may be positioned in such a way that it does not significantly affect the diamond’s aesthetic quality.

Impact of Knots on Diamond Value
Knots can reduce a diamond’s market value, as they negatively affect its clarity and appearance. The extent of the impact on value depends on several factors:

Size of the Knot: Larger knots, particularly those visible to the naked eye, will generally result in a more significant reduction in value.
Location of the Knot: Knots located in more visible areas, such as the crown or table, will have a greater impact on the diamond’s appearance and thus its value. Conversely, knots located on the pavilion (bottom) or near the girdle may be less noticeable.
Number of Knots: Diamonds with multiple knots may be valued lower than those with fewer or no inclusions. However, some diamonds may contain one or two small knots that do not significantly affect their overall appearance or value.
Knot vs. Other Inclusions
While a knot is a relatively specific type of inclusion, it is useful to compare it with other types of diamond inclusions:

Crystal: Similar to a knot, a crystal is an inclusion of another mineral within the diamond. However, unlike a knot, a crystal does not necessarily break through the surface of the diamond.
Feather: A feather is another inclusion that can sometimes reach the surface of the diamond. Unlike knots, feathers are typically fissures or cracks in the diamond that may or may not affect the clarity grade.
Needle: A needle inclusion is a thin, elongated inclusion that does not typically reach the surface of the diamond, and thus may not be as impactful as a knot.
Treatment of Knots
In some cases, diamond cutters may attempt to minimise the visual impact of a knot by carefully positioning it or by using techniques like laser drilling to remove or reduce the visibility of inclusions. However, the presence of a knot often cannot be completely eliminated, particularly if the knot is close to the surface.

Additionally, some diamonds with prominent knots may be treated by laser inscription, which may help with traceability but will not alter the presence of the knot itself.

July, 2017February, 2025

Laser Drilling

Laser drilling is a treatment used to enhance the apparent clarity of a diamond by reducing the visibility of dark inclusions. It involves the use of a focused laser beam to create a small tunnel through the diamond’s surface, allowing the removal or bleaching of inclusions, particularly dark ones. This process is commonly used to improve the visual appeal of diamonds with noticeable inclusions, making them more attractive to potential buyers. While laser drilling is an effective technique, it’s important to understand its process, benefits, and potential drawbacks.

The Laser Drilling Process
Laser drilling is a highly precise technique that typically follows these steps:

Identification of Inclusions: Before the drilling process begins, the diamond is thoroughly examined to identify the inclusions that can be treated. Dark inclusions, such as black carbon spots or crystals, are the primary targets of this treatment, as they are often the most visible and detrimental to a diamond’s clarity.

Laser Penetration: Once the target inclusions are located, a small laser beam is directed at the diamond. The laser drills a tiny tunnel from the surface to the inclusion, carefully creating a channel that reaches the inclusion without compromising the integrity of the diamond. This process is highly precise, and the depth and location of the drill are controlled to ensure the best possible results without causing damage.

Inclusion Removal or Bleaching: After the tunnel is created, the dark inclusion inside the diamond is either:

Vaporised: In some cases, the laser’s intense heat will cause the dark material in the inclusion to evaporate, making it less noticeable.
Bleached: Alternatively, if the inclusion is resistant to laser vaporisation, the material is often bleached with a mild acid solution. This is particularly effective for black carbon or graphite inclusions. The bleaching process lightens or removes the dark colour, making the inclusion less visible to the naked eye.
Surface Finishing: After the treatment, the surface of the diamond may require some polishing or additional treatment to restore its smoothness and appearance. The treated areas are carefully examined to ensure that the diamond’s clarity is visibly improved.

Types of Inclusions Treated by Laser Drilling
Laser drilling is most commonly used to treat specific types of inclusions, primarily those that significantly affect a diamond’s clarity and appearance:

Black Inclusions: These are often caused by carbon or graphite inclusions, which appear as dark spots or crystals inside the diamond. These inclusions are particularly noticeable and can dramatically affect the visual quality of the diamond. Laser drilling is effective in removing or lightening these dark inclusions.

Crystal Inclusions: If a crystal inclusion is dark in colour, laser drilling may be used to reduce its visibility. Crystal inclusions are common in diamonds, and laser drilling can help make them less conspicuous without affecting the structural integrity of the diamond.

Feathers: In some cases, laser drilling can be used to treat smaller feather-like inclusions that have a darker colour. While the primary purpose of laser drilling is to target black inclusions, it can sometimes be effective for other types of inclusions that detract from the diamond’s clarity.

Benefits of Laser Drilling
Improved Clarity: The main benefit of laser drilling is its ability to significantly enhance the clarity of a diamond. By reducing the visibility of dark inclusions, the diamond appears clearer and more visually appealing, which can increase its marketability and value.

Preserving Diamond Integrity: Unlike some other clarity-enhancing treatments, laser drilling does not compromise the structural integrity of the diamond. The process is highly precise and controlled, ensuring that the diamond remains intact and safe for regular wear.

Affordable Alternative to Higher-Quality Diamonds: Laser drilling can be a more cost-effective solution for diamonds that would otherwise be deemed lower in clarity. This treatment can make diamonds with minor inclusions more appealing, potentially allowing them to be sold at a higher price point.

Customised Treatment: The precision of the laser drilling process means that diamonds can be treated on a case-by-case basis. This customisation allows diamond professionals to target only the inclusions that are most visible and impactful, ensuring that the treatment is both effective and minimally invasive.

Drawbacks and Considerations
While laser drilling offers several benefits, it’s important to consider the potential drawbacks of this treatment:

Visible Marks on the Surface: Laser drilling creates small tunnels or entry points on the diamond’s surface. Although these are typically very small and can be polished after treatment, they may still be visible under magnification. These marks can slightly detract from the overall appearance of the diamond, particularly in higher magnification grades.

Affecting Diamond Value: While laser drilling can improve the clarity of a diamond, it is important to note that diamonds treated with laser drilling may be graded differently than untreated diamonds. In some cases, diamonds that have undergone laser drilling may be valued lower than those with naturally high clarity because the treatment is considered an enhancement, rather than a natural characteristic.

Potential Disclosure Requirements: If a diamond has been laser drilled, it must be disclosed to potential buyers. Ethical guidelines and diamond grading standards require that treatments such as laser drilling be properly documented and disclosed, which means buyers will be aware of the enhancement.

Limitations on Severe Inclusions: While laser drilling can be highly effective for small dark inclusions, it is not always appropriate for larger or more complex inclusions. For example, if the inclusion extends too far into the diamond, or if it is located in a position where drilling is difficult or would risk damaging the diamond, laser drilling may not be feasible.

Laser Drilling vs. Other Diamond Treatments
Clarity Enhancement via Bleaching: Laser drilling is often used in conjunction with other clarity-enhancing treatments such as laser bleaching, where the dark inclusion is lightened with acid. While both techniques aim to reduce the visibility of inclusions, laser drilling focuses on creating a tunnel to remove or lighten the inclusion, while bleaching lightens the inclusion chemically.

Fracture Filling: Another clarity-enhancing treatment is fracture filling, which involves filling small fractures or inclusions with a substance such as glass or resin to make them less visible. Laser drilling is sometimes used in conjunction with fracture filling to target dark inclusions that are visible on the diamond’s surface.