Rough Diamond – Page 54 – The Diamond Certification Laboratory of Australia (DCLA)

July, 2017February, 2025

Crown

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.

July, 2017February, 2025

Crown Angle

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.

July, 2017February, 2025

Crown Height

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.

July, 2017February, 2025

Conflict Diamonds

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.

July, 2017February, 2025

Colour

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.

July, 2017February, 2025

Coloured Diamond

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.

July, 2017February, 2025

Coated Diamond or Coating

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.

July, 2017February, 2025

Cognac

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.

July, 2017February, 2025

Cold Laser Inscription

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.

July, 2017February, 2025

Cleavage

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.