The Diamond Certification Laboratory of Australia (DCLA)

The diamond make refers to the overall quality of the cut of a diamond, evaluating how well it has been shaped and finished. This includes an assessment of the proportions, symmetry, and polish of the diamond, all of which contribute to its brilliance, fire, and scintillation (the sparkle of the diamond). The make plays a crucial role in determining the diamond’s visual appeal and its overall value. A well-cut diamond will exhibit optimal light performance, making it appear vibrant and full of life.

Key Aspects of Diamond Make
Proportions:

The proportions of a diamond are crucial to its overall make. This refers to the specific dimensions of the diamond, including the depth, table, crown angle, pavilion angle, and the girdle. The proportions must be balanced in such a way that they allow for the ideal reflection and refraction of light, maximising the diamond’s brilliance.
Ideal Proportions: For a round brilliant cut diamond, the ideal proportions ensure that light entering the diamond is properly reflected and refracted, bouncing around the facets before exiting through the crown and creating sparkle.
Poor Proportions: A diamond with poor proportions will either leak light out from the bottom (leading to a dark, dull appearance) or fail to reflect light properly (causing a lifeless look).
Symmetry:

Symmetry refers to the precision and alignment of the facets in a diamond. A well-symmetrical diamond ensures that each facet is positioned correctly to reflect light at the right angles. For round brilliant cuts, symmetry affects how well the facets align to create the signature sparkle. Any asymmetry, such as off-centre facets or mismatched angles, will interfere with the flow of light and negatively impact the diamond’s overall performance.
Ideal Symmetry: A diamond with excellent symmetry will display uniformity across all facets, contributing to a balanced distribution of light and a consistent sparkle.
Poor Symmetry: A diamond with poor symmetry may display uneven facets, which can affect the visual appearance and reduce its brilliance.
Polish:

Polish refers to the smoothness and finish of the diamond’s surfaces, including the crown, pavilion, and girdle. A well-polished diamond allows light to pass through smoothly, enhancing its brilliance and preventing light from being blocked by rough or uneven surfaces.
Ideal Polish: Diamonds with excellent polish will have a smooth, flawless surface that reflects light optimally. There will be no visible abrasions, scratches, or imperfections on the surface.
Poor Polish: If the diamond is poorly polished, the surface may have visible blemishes, which can distort the light and detract from the diamond’s overall sparkle.
Cut Grade:

The cut grade is a composite evaluation that includes the proportions, symmetry, and polish of the diamond. Diamond grading laboratories, such as the Gemological Institute of America (GIA), assign cut grades that range from Excellent to Poor based on these factors. A diamond with an excellent cut will showcase ideal proportions, symmetry, and polish, leading to superior brilliance and fire.
Ideal Cut: A diamond with an ideal cut is precisely shaped to reflect light in the most efficient way, maximising its brilliance and visual appeal.
Good/Very Good Cut: These diamonds may have minor deviations from ideal proportions or symmetry, but they still exhibit strong light performance.
Fair/Poor Cut: These diamonds have significant deviations from the ideal, which can lead to dull or lifeless appearances.
Impact of Diamond Make on Light Performance
The make of a diamond directly influences how light is handled by the stone. When light enters a diamond, it travels through the crown and pavilion before exiting, either through the top (creating brilliance) or dispersing into a spectrum of colours (creating fire). The cut quality determines how well this light is managed and returned to the observer’s eye.

Brilliance:

A diamond’s brilliance is the amount of white light it reflects. A well-cut diamond with excellent proportions and symmetry will reflect light efficiently, leading to a bright and lively appearance.
Fire:

Fire refers to the dispersion of light into a spectrum of colours, similar to a rainbow. Diamonds with an excellent make will show vibrant flashes of colour, enhancing the overall beauty and desirability of the stone.
Scintillation:

Scintillation refers to the flashes of light seen when the diamond moves. A well-cut diamond will exhibit a high degree of scintillation, making it appear sparkling and dynamic as it shifts in the light.
Importance of Diamond Make in Valuation
The make of a diamond significantly affects its value. Diamonds with excellent makes are highly sought after and are often priced higher because they exhibit superior light performance and visual appeal. In contrast, diamonds with poor makes may be priced lower due to their less-than-optimal appearance.

High-Quality Make: Diamonds with excellent cuts, symmetry, and polish will be more valuable due to their superior brilliance, fire, and scintillation. These diamonds are also more desirable to consumers, who often seek the most visually stunning stones.

Low-Quality Make: Diamonds with poor cuts, imbalanced proportions, or visible imperfections on the surface will likely be less valuable. These diamonds do not reflect light as efficiently, resulting in a duller appearance and lower demand in the market.

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.

A Master Set is a collection of certified and registered diamonds that serve as a reference point for grading the colour of other diamonds. The diamonds in a master set are chosen for their precise and consistent colour characteristics, and each diamond is individually classified within a particular colour range, often ranging from colourless (D) to light yellow or brown (Z), according to the GIA Colour Scale or other recognised grading standards.

The purpose of a master set is to provide an objective standard for comparing and accurately assessing the colour of diamonds during the grading process. By using a Master Set, diamond graders can ensure consistency and accuracy in colour grading, as the reference stones provide a benchmark for evaluating diamonds’ hues. This process helps to eliminate subjective biases and increases the reliability of the grading results.

Key Features of a Master Set
Certified Diamonds:

Each diamond in the Master Set is certified by a reputable grading laboratory (e.g., GIA, HRD, or IGI) and comes with detailed records of its colour grading. These records provide precise information on the diamond’s colour grade, ensuring that the diamonds in the master set are trustworthy reference points for grading other stones.
Colour Range:

A Master Set includes diamonds across a range of colours, typically from colourless (Grade D) to light yellow or light brown (Grade Z). This range allows graders to compare the colour of a diamond with various reference stones, ensuring the most accurate and consistent results.
The diamonds in the set are usually classified based on their natural colour without any treatments, as colour-treated diamonds require different grading protocols.
Standardised Comparison:

The diamonds in the Master Set act as comparison stones for assessing other diamonds. By placing a diamond next to the certified stones in the set, graders can easily match the colour and assign it an appropriate grade based on its similarity to the reference stones.
This ensures that all diamonds are graded using the same objective criteria, regardless of the individual grader’s experience or judgment.
Registered Diamonds:

Diamonds in a Master Set are registered, which means they have been officially documented with a specific set of characteristics, including the colour grade. Registration ensures that each stone in the set can be tracked and used as a consistent reference tool.
The process of registration typically involves documenting the specific colour and characteristics of each diamond in a record that can be easily accessed by industry professionals.
Essential for Accurate Colour Grading:

A Master Set is essential for accurate diamond colour grading, as it provides an objective, widely accepted standard. Without a master set, the grading process would be less consistent, with a higher risk of discrepancies due to subjective variations.
The set is a tool that helps to standardise the grading of diamonds, ensuring that diamonds are consistently assessed against a well-defined set of reference stones.
Types of Master Sets
First-Generation Master Set:

The first-generation Master Set is available to any diamond merchant or jeweller and serves as the foundation for colour grading. It provides a broad range of reference diamonds and is often used in various settings, including retail jewellery stores, grading laboratories, and diamond trading.
These sets are typically updated periodically to maintain their relevance and accuracy, especially as diamond grading techniques and standards evolve over time.
Second and Subsequent Generations:

Second-generation and further updated Master Sets are typically more refined and may contain diamonds that are more carefully selected for consistency, quality, and precision. These sets may also include additional diamonds for more specific colour grading needs, such as diamonds with rare or exceptional colour characteristics.
These sets may be used by professional grading laboratories, where a higher level of precision and consistency is required for industry-leading accuracy.
Role of a Master Set in the Diamond Industry
Ensuring Consistency in the Diamond Market:

The use of Master Sets helps to ensure that diamonds are graded consistently across different grading laboratories and diamond merchants. This is critical for maintaining trust in the diamond industry and protecting consumers from inaccurate or misleading grading.
By using a Master Set, buyers and sellers can have more confidence that diamonds with similar colour grades will be priced similarly, helping to standardise the market and reduce confusion.
Facilitating International Trade:

The Master Set is an important tool for facilitating international diamond trade. It ensures that diamonds from different countries or regions are evaluated using the same standards, which is particularly important when diamonds are being sold across borders.
International grading consistency ensures that diamonds are accurately represented, and buyers can trust that the diamonds they purchase meet the grading standards they expect.
Improving Grading Accuracy in Laboratories:

Diamond grading laboratories rely heavily on Master Sets to calibrate their equipment and maintain the accuracy of their grading systems. These sets are used to train new graders and ensure that all grading personnel are aligned on how to assess the colour of diamonds.
Master Sets are essential for laboratory quality control procedures, ensuring that diamonds are consistently graded according to the highest standards of accuracy.

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.

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.

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.

Moissanite is a gemstone made of silicon carbide (SiC) that closely resembles a diamond in appearance but has distinct physical and optical properties. Originally discovered in 1893 by Henri Moissan, a French chemist, moissanite was first found in a meteorite crater and was initially mistaken for a diamond. Natural moissanite is extremely rare, so all moissanite gemstones available in jewelry today are lab-created.

Moissanite vs. Diamond – Key Differences
Property Moissanite Diamond
Composition Silicon carbide (SiC) Carbon (C)
Hardness (Mohs Scale) 9.25 (very hard, second only to diamond) 10 (hardest natural material)
Brilliance (Refractive Index) 2.65–2.69 (higher brilliance than diamond) 2.42
Dispersion (Fire) 0.104 (more fire, creating rainbow flashes of light) 0.044
Toughness Excellent Excellent
Price Much lower than diamond Higher, especially for natural diamonds
Rarity Lab-created Natural or lab-grown
Fluorescence May have faint fluorescence Can range from none to strong
Ethical Considerations Conflict-free, eco-friendly Natural diamonds may have ethical sourcing concerns
Moissanite’s Optical Properties
One of the most notable differences between moissanite and diamond is its higher refractive index (2.65–2.69), which results in greater brilliance and fire (the dispersion of light into rainbow colors). This makes moissanite appear more sparkly, especially under bright light.

Some people find this extra fire appealing, while others prefer the more subtle, pure white sparkle of diamonds.

Durability and Hardness
Moissanite is extremely durable, with a Mohs hardness of 9.25, making it the second hardest gemstone after diamond (10). It is resistant to scratching, making it an excellent choice for engagement rings and everyday jewelry.

Price and Affordability
Moissanite is significantly more affordable than diamonds of comparable size and quality.

A 1-carat moissanite costs a fraction of the price of a 1-carat diamond.
The cost does not increase exponentially with size, as it does with diamonds.
Moissanite as a Diamond Alternative
Because of its brilliance, durability, and affordability, moissanite is a popular alternative to diamonds, particularly for engagement rings and fine jewelry. Many people choose moissanite for its ethical and eco-friendly benefits, as it is lab-created and does not involve mining.