Toughness

Toughness Measure of brittleness, or resistance to fracture and breaking

Toughness refers to a diamond’s resistance to fracture or breaking when subjected to impact or stress. While diamonds are known for their exceptional hardness, which allows them to resist scratching and abrasion, toughness measures how well a diamond can withstand physical force, such as chipping or cracking. Toughness is an essential characteristic when evaluating the durability of a diamond, particularly when it comes to everyday wear and usage in jewellery.

Though diamonds are one of the hardest materials on Earth, they are not immune to damage. Due to the crystal structure of diamonds, they have certain planes of weakness that can make them susceptible to breaking if impacted along these planes. Therefore, while a diamond may not scratch easily, it can still fracture or split under the right conditions. This makes toughness an important factor in assessing how a diamond will perform in real-world scenarios, such as in rings or other jewellery that is regularly exposed to physical stress.

Understanding Diamond Toughness:
Hardness vs. Toughness:

Hardness refers to a material’s ability to resist scratching, and diamonds are the hardest known natural substance, scoring a 10 on the Mohs scale of hardness.
Toughness, on the other hand, refers to how well a material can absorb energy without breaking or fracturing. While diamonds are incredibly hard, they are not as tough as some other materials due to their brittleness. This means that while diamonds can resist scratching, they may be more prone to chipping or cracking if hit at certain angles.
Directional Hardness:

One of the key factors influencing the toughness of a diamond is its directional hardness. Diamonds have a crystal structure known as cubic or isometric, which means that their atoms are arranged in a specific way that makes them incredibly hard in certain directions but more vulnerable in others.
While the diamond is extremely hard along its axes, this structural alignment can make it more prone to cleaving or splitting along certain planes, especially when it experiences a strong impact. These planes of weakness make diamonds more fragile in some situations, particularly if subjected to sharp blows or pressure.
Toughness Rating:

Diamonds do not have a standard toughness rating in the same way that they are graded for hardness. However, toughness is typically described in terms of how resistant a diamond is to breaking, chipping, or fracturing.
Toughness can be affected by factors such as the quality of the cut, inclusions, and fractures present in the diamond. A diamond with significant internal flaws, such as inclusions, may be less tough and more likely to break or chip under stress than a flawless diamond.
Factors Influencing Diamond Toughness:

Clarity: Diamonds with inclusions or internal fractures are generally more prone to breakage. These internal weaknesses can compromise the diamond’s toughness, making it more vulnerable to impact.
Cut Quality: A well-cut diamond with proper proportions and symmetry will often be more durable, as the cut will reduce the likelihood of creating stress points where fractures could occur. A poorly cut diamond may have internal tensions that make it more fragile.
Size and Shape: Larger diamonds or diamonds with more complex shapes (like those with sharp corners or thin edges) may be more susceptible to chipping or fracturing if impacted. The shape and overall structure of the diamond can affect its ability to absorb force without damage.
Real-World Application:

While diamonds are the hardest known material, their brittleness means that they need to be handled with care. Diamonds used in jewellery, such as engagement rings or bracelets, are typically designed to avoid exposure to significant impact or stress.
For example, diamonds with sharp corners (like princess cut diamonds) or thin edges (like emerald cut diamonds) may be more susceptible to chipping than those with rounder shapes, such as the round brilliant cut, which typically has a stronger overall structure.
Bezel settings or halo settings in jewellery can offer additional protection to the diamond, keeping it shielded from accidental impact.
Toughness in Coloured Diamonds:

While most of the principles regarding diamond toughness apply to colourless diamonds, coloured diamonds may have their own unique challenges. For example, some coloured diamonds, especially those with intense colours like red or blue, may have inclusions or internal characteristics that affect their toughness.
Coloured diamonds, due to their often unique internal structures, may exhibit slightly different behaviour under impact, but they still share the same basic brittleness as other diamonds.
Toughness and Diamond Jewellery:

When choosing a diamond for daily wear jewellery, toughness is an important consideration, especially for items like engagement rings, which are subject to constant wear and potential impact.
A diamond’s setting also plays a role in how well it can withstand rough treatment. A prong setting, for example, may expose the diamond to more risk of damage, while a bezel setting can offer more protection.

Diamond toughness is an essential characteristic that determines a diamond’s ability to withstand impact and stress without fracturing or breaking. Although diamonds are the hardest material on Earth, their brittleness means they can still break along planes of weakness in their crystal structure. Therefore, toughness is closely linked to hardness but involves how well a diamond resists fractures, chips, and cracks from physical force. When choosing a diamond for jewellery, it is important to consider the diamond’s clarity, cut, and shape, as these factors can influence the diamond’s overall toughness and resistance to damage.

Table

The table is one of the most important facets of a polished diamond, situated at the very top of the diamond, in the crown area. It is the largest flat facet on the diamond and plays a crucial role in how light interacts with the stone. The table facet is typically positioned parallel to the girdle, which is the outermost edge of the diamond, and it serves as a window through which light enters and exits the diamond. The size and proportion of the table facet significantly impact the overall appearance, brilliance, and sparkle of the diamond.

Position and Shape:
The table is flat and circular in shape, with its size and dimensions typically defined as a percentage of the diameter of the diamond, measured from the girdle.
It is placed directly at the top of the diamond, centered on the crown. For round brilliant cut diamonds, the table should be symmetrical to allow for even light reflection and maximum brilliance.
The size of the table relative to the overall dimensions of the diamond is an important factor in its overall cut quality and light performance. A table that is too large or too small can negatively affect the diamond’s visual appeal.
Role of the Table in Diamond Brilliance:
The table facet is the primary surface through which light enters the diamond, and its quality directly influences the diamond’s brilliance (the amount of white light reflected). Light entering the table facet is refracted through the diamond’s other facets, creating the sparkle and life that is characteristic of a well-cut diamond.
If the table is too large, it may result in excessive light leakage, where light passes through the bottom of the diamond, reducing its brilliance. Conversely, a table that is too small may limit the diamond’s ability to reflect light effectively, making the diamond appear darker or less vibrant.
Table and Diamond Cut Quality:
The size of the table is one of the key factors considered when assessing a diamond’s cut grade. The table-to-depth ratio is calculated by measuring the table’s diameter and comparing it to the diamond’s overall depth. An ideal round brilliant cut diamond typically has a table size that falls within a certain percentage range of its overall diameter, usually between 53% and 58% for optimal brilliance.

Ideal Table Size: For round brilliant cut diamonds, an ideal table size typically falls between 53% and 58% of the overall diameter, balancing light reflection and maximizing brilliance.
Large Table: A diamond with an excessively large table relative to its depth may reflect less light, leading to a loss of brilliance and a flat appearance. In contrast, a smaller table could result in a diamond that looks darker or less reflective.
Table in Fancy Shapes:
While the table is a key feature in all diamonds, it is especially important for round brilliant cut diamonds. In fancy-shaped diamonds, such as princess, emerald, and asscher cuts, the table may vary slightly in shape and size to accommodate the unique proportions and angles of each cut. However, the role of the table in influencing light entry and brilliance remains consistent across all diamond shapes.

DCLA and Table Quality:
The Diamond Certification Laboratory of Australia (DCLA) is one of the leading authorities in diamond grading and certification, particularly within the Australian market. When a diamond is graded by DCLA, the table is assessed as part of the overall cut grade. DCLA uses a comprehensive set of criteria to evaluate all facets of the diamond, including the table facet.

The table is evaluated for size, symmetry, and alignment, ensuring that it contributes to the overall quality of the cut and the diamond’s ability to reflect light properly.
DCLA reports provide detailed information about the table size in relation to the diamond’s total diameter, helping consumers and investors understand how the table contributes to the diamond’s brilliance and overall visual appeal.
DCLA also measures the proportions of the table and other facets, ensuring that the diamond meets industry standards for ideal proportions. The laboratory’s expertise in evaluating the table facet, alongside other critical attributes like crown angle and pavilion depth, ensures that each diamond receives a thorough and accurate grading report that reflects its true quality.

Table and Diamond Certification:
In the grading report issued by DCLA, the table facet is one of the important details that helps determine the diamond’s overall cut grade. Since the cut is a significant factor in determining the diamond’s beauty and value, the size, proportions, and finish of the table are carefully examined. A well-proportioned table enhances the diamond’s light performance, while an incorrect or poorly finished table can result in suboptimal visual appeal.

In addition to the table’s size, the report may also include additional information about the table’s polish, symmetry, and overall surface quality, as these factors all influence the diamond’s final appearance.

The table is a crucial facet in determining a diamond’s overall beauty and brilliance. Its size, shape, and position play a vital role in how the diamond interacts with light and contributes to the diamond’s overall sparkle and visual appeal. Whether it is a round brilliant cut diamond or a fancy shape, the quality and proportions of the table can significantly affect the diamond’s grade and value. The DCLA ensures that diamonds are thoroughly assessed and accurately graded, with special attention to the table’s impact on the diamond’s overall cut quality and performance.

Table Size

Table size refers to the measurement of the table facet of a diamond, which is the large, flat surface located on the top of the stone. It is expressed as a percentage of the diameter of the diamond. The table size is a crucial factor in determining the overall appearance and brilliance of the diamond. It plays an essential role in balancing brilliance (the white light reflected from the diamond) and dispersion (the colourful flashes of light that come from the diamond’s facets).

Table Size and its Impact on Brilliance and Fire:
Brilliance: A well-proportioned table allows for an optimal amount of light to enter the diamond, reflect off the facets inside, and return to the viewer’s eye. The table size is an essential factor that helps to achieve maximum brilliance. When the table is too large, more light may leak out from the bottom of the diamond, reducing brilliance. A table that is too small may limit light reflection, resulting in a dull appearance.
Dispersion (Fire): Dispersion is the colourful flashes of light that a diamond emits when it is moved or viewed under direct light. The table size also affects how much dispersion is visible. A properly proportioned table will allow for the best balance between brilliance (white light) and fire (colourful flashes). If the table size is too large, it may decrease the intensity of the dispersion, as the light may not be effectively refracted and split into different colours.
How Table Size is Measured:
Table Size as a Percentage: Table size is typically expressed as a percentage, representing the diameter of the table facet in relation to the overall diameter of the diamond. For example, if the table diameter is 5mm and the overall diameter of the diamond is 8mm, the table size would be calculated as:
Table Size Percentage

Table Size Percentage=(85)×100=62.5%


This means the table facet makes up 62.5% of the total diameter of the diamond.
Ideal Table Size:
For round brilliant cut diamonds, the ideal table size typically falls within the 53% to 58% range of the diamond’s total diameter. This proportion allows for the best balance of light reflection and brilliance, ensuring the diamond appears vibrant and sparkling. When the table is within this ideal range, it enhances the diamond’s overall performance by optimising how it handles light.

Ideal Range: A table size between 53% and 58% is generally considered ideal for round brilliant cut diamonds. Diamonds with table sizes within this range tend to exhibit excellent brilliance and light performance.
Larger Table Sizes: A table size that is larger than 58% may reduce the amount of light that is reflected, resulting in lower brilliance. This can make the diamond appear flat and less lively.
Smaller Table Sizes: A table size smaller than 53% may limit the amount of light that enters the diamond, reducing its sparkle and making the diamond look darker or duller.
Table Size and Diamond Grading:
The table size is one of the factors assessed when determining the cut grade of a diamond, particularly in round brilliant cut diamonds. The cut grade reflects the overall quality of the diamond’s proportions, symmetry, and polish, and it has a significant impact on the diamond’s brilliance and value.

Proportions: Table size is a crucial part of the overall proportions of a diamond, and it works in conjunction with other factors such as crown angle, pavilion depth, and girdle thickness to determine the overall quality of the cut.
Diamond Certification: Leading diamond grading laboratories, such as the DCLA (Diamond Certification Laboratory of Australia), carefully assess the table size when providing a grading report. They ensure that the table size falls within an acceptable range for the diamond’s shape and type to guarantee the best possible visual performance.
Fancy-Shaped Diamonds and Table Size:
While table size is most commonly associated with round brilliant cut diamonds, it also applies to other fancy-shaped diamonds, such as emerald cut, asscher cut, princess cut, and oval cut diamonds. However, for fancy shapes, the ideal table size may vary depending on the shape and the proportions of the diamond. For example:

Princess Cut Diamonds: In a princess cut diamond, the table size is usually larger relative to the overall size, often in the 60% to 70% range. This helps to achieve the maximum brilliance and visual appeal.
Emerald Cut Diamonds: Due to their step-cut faceting, emerald cut diamonds tend to have a larger table relative to their overall size, often ranging from 60% to 70% as well. The larger table enhances the clarity of the diamond, allowing the observer to better appreciate its internal characteristics.
Factors Affecting Table Size:
Several factors can influence the size of the table facet on a diamond:

Cutting Style: The cutting style of the diamond affects the table size. Round brilliant cuts are often cut with a smaller table, while other cuts like princess and emerald may have larger tables.
Diamond Size: Larger diamonds often have larger table sizes, as their proportions allow for more substantial table facets without sacrificing the diamond’s brilliance.
Manufacturer Preferences: Some diamond manufacturers may adjust the table size to meet specific aesthetic or performance goals, influencing the final appearance of the diamond.

The table size of a diamond is a crucial factor that significantly influences its brilliance and fire. It is measured as a percentage of the diamond’s overall diameter, and its proper proportion ensures the diamond displays optimal light performance. For round brilliant cut diamonds, the ideal table size typically falls within the 53% to 58% range, although fancy-shaped diamonds may have varying table sizes depending on their unique cutting styles. Properly balanced table size, along with other critical cut factors, contributes to a diamond’s overall beauty, value, and appeal. The DCLA and other leading certification labs evaluate table size as part of the comprehensive cut grading process, ensuring that the diamond performs to its fullest potential.

 

 

 

 

Symmetry

Symmetry Degree and regularity in shape and placement of facets

Symmetry in a diamond refers to the degree of alignment and uniformity in the shape and placement of its facets. It describes how well the facets of the diamond align with one another, creating a harmonious, balanced structure. High symmetry ensures that each facet is positioned correctly and consistently, contributing to the overall beauty, brilliance, and sparkle of the diamond.

Importance of Symmetry in Diamonds:
Light Reflection and Refraction: The primary reason symmetry is so crucial is because it directly impacts the light performance of the diamond. A diamond with imperfect symmetry will not reflect and refract light as efficiently as one with perfect symmetry. The facets are responsible for bouncing light throughout the diamond, and when they are aligned symmetrically, they allow light to be returned to the eye in a uniform and harmonious way, increasing the diamond’s brilliance and fire. Asymmetry, on the other hand, may cause the light to be dispersed unevenly, leading to a less vibrant or dull appearance.

Brilliance and Sparkle: Symmetry is one of the key contributors to a diamond’s brilliance (the return of white light) and scintillation (the flashes of colour and sparkle as the diamond moves). When the facets are well-aligned and symmetrical, they work together to reflect and direct light, producing more intense sparkle. For example, round brilliant-cut diamonds are famous for displaying hearts and arrows patterns (a symmetrical optical effect visible under magnification), which are a direct result of precise symmetry in the cut.

Consistency Across Facets: In well-cut diamonds, symmetry means that the size, shape, and placement of each facet are consistent, whether it’s in a round brilliant, emerald cut, or any other shape. In a round brilliant cut diamond, for example, all the upper and lower facets (including the star facets, bezel facets, and pavilion facets) should be of equal size and alignment to create a seamless and balanced look. Even minor deviations can affect the diamond’s overall visual appeal.

Impact of Symmetry on Diamond Grading:
Diamond Grading: The symmetry of a diamond is evaluated as part of the overall cut grade, which is one of the four Cs (Carat, Cut, Colour, and Clarity). Diamonds with perfect symmetry often receive higher grades, as their precise proportions enhance both aesthetic beauty and light performance. Symmetry is graded on a scale that can range from Excellent to Poor, depending on how accurately the facets align and match each other.

Perfect Symmetry: A diamond with perfect symmetry has facets that are so well-aligned that they create a balanced, flawless reflection of light. This is often seen in high-quality diamonds, where precision cutting is paramount.

Symmetry in Fancy Cuts: While symmetry is often most easily assessed in round brilliant cut diamonds, it is also important in other fancy cuts like the emerald cut, princess cut, or radiant cut. For example, in an emerald cut, symmetry can be seen in the parallel arrangement of the facets, and the alignment of corners should be perfect to achieve a clean, even look.

Hearts and Arrows:
In round brilliant cut diamonds, symmetry is so precise that it can create a distinct pattern known as hearts and arrows. When viewed under magnification, a well-cut round brilliant diamond will reveal a heart-shaped pattern on the bottom of the diamond (the pavilion) and arrow-shaped patterns on the top (the crown). These patterns are a clear indication of exceptional symmetry and contribute to the diamond’s perceived perfection.

Hearts and Arrows: The hearts and arrows pattern is highly prized in diamonds, particularly those cut to the highest standards of symmetry. It is a rare phenomenon that occurs only when the diamond’s facets are aligned so precisely that they reflect light in a perfect, symmetrical manner.
Symmetry in Other Cuts:
Symmetry is also vital in fancy-shaped diamonds (e.g., pear, oval, asscher, and radiant cuts). For instance:

In oval-cut diamonds, symmetry is judged by how well the curves of the diamond are evenly shaped and balanced.
In princess-cut diamonds, the symmetry of the corners and the alignment of facets is crucial to creating a visually appealing and well-proportioned diamond.

Symmetry is an essential factor that determines the overall beauty and performance of a diamond. It directly influences how the diamond interacts with light, impacting its brilliance, fire, and scintillation. Symmetrical diamonds are not only more visually appealing but also demonstrate higher cut quality, which is why symmetry is one of the main criteria in diamond grading. Whether it’s a round brilliant showing hearts and arrows or a fancy cut with perfectly aligned facets, symmetry plays a vital role in ensuring that a diamond sparkles to its fullest potential.

Step Cut

Step Cut A style of diamond cutting creating rows or steps of elongated facets

A step cut is a style of diamond cutting that creates a distinctive look with rows or steps of elongated facets. These facets run parallel to the girdle of the diamond on both the crown (the upper portion) and the pavilion (the lower portion). The step cut is known for its classic, elegant appearance and is often used in diamonds with larger surface areas.

Key Features of Step Cut Diamonds:
Faceting Style: The defining characteristic of the step cut is the linear arrangement of facets, which resemble steps or rows. These elongated facets create a staircase-like effect, with the facets running parallel to the girdle of the diamond. This cut contrasts with the brilliant cut, which features numerous triangular and kite-shaped facets to reflect light in a more dynamic way.

Popular Step Cuts: Two of the most famous step cut diamond shapes are the emerald cut and the baguette cut:

Emerald Cut: The emerald cut is a rectangular or square-shaped diamond with cut corners. It features large, rectangular facets that showcase the diamond’s clarity and colour. The emerald cut is known for its elegant, understated beauty.
Baguette Cut: Typically smaller and more elongated, the baguette cut features long, rectangular facets and is often used as an accent stone or in vintage-style jewellery.
Facets and Symmetry: In a step cut, the facets are typically rectangular and arranged in a way that each one is aligned with the others, creating a step-like appearance. These facets are often fewer in number than those found in brilliant cuts, which gives step-cut diamonds a more minimalist and elegant appearance.

Clarity Emphasis: Step cuts, particularly the emerald cut, are often chosen for diamonds with high clarity because they showcase internal inclusions more prominently than a round brilliant cut. The large, flat facets on step-cut diamonds allow for a clearer view into the diamond, making it important to choose a stone with minimal visible flaws for the best visual appeal.

Light Reflection: Unlike brilliant cuts, which are designed to reflect light in many directions to create sparkle, the step cut focuses on creating a more subdued, reflective appearance. The large facets reflect light in a more linear way, and while step-cut diamonds might not have the same intense sparkle as a round brilliant cut, they often display a unique glow that comes from the reflection of light off their smooth, flat surfaces. This makes step-cut diamonds more suited for those who appreciate elegance and clarity over sparkle.

Advantages of Step Cut Diamonds:
Clarity Visibility: Step cuts are perfect for diamonds with excellent clarity because they allow you to see the diamond’s interior more clearly. This cut tends to highlight a diamond’s cleanliness and colour.

Sophisticated and Timeless: The elegant, understated look of step-cut diamonds makes them a favourite choice for those who prefer a more classic and timeless design. They often lend themselves to vintage-style or art-deco designs.

Better for Larger Stones: Step cuts tend to work well with larger diamonds because they allow the stone’s size to be appreciated without excessive light dispersion, which can make smaller diamonds appear less impressive. The open facet structure in step cuts can give larger diamonds a cleaner and more sophisticated appearance.

Disadvantages of Step Cut Diamonds:
Less Sparkle: While step-cut diamonds still possess beauty and brilliance, they do not reflect light in the same way that brilliant-cut diamonds do. The less intense sparkle can make them less desirable for those who prefer the flashy brilliance associated with modern cuts.

Visibility of Inclusions: Step cuts can make internal inclusions or imperfections more visible due to the large, open facets. Therefore, diamonds with higher clarity are preferred for step-cut styles to avoid any noticeable flaws.

The step cut is a refined and elegant diamond cutting style that emphasises clarity and colour over intense sparkle. With its distinct rows of elongated facets running parallel to the girdle, step-cut diamonds (like the emerald and baguette cuts) offer a timeless aesthetic that appeals to those seeking sophistication and simplicity. This cut is particularly well-suited for larger diamonds and stones with high clarity, and while it may not produce the same level of sparkle as a brilliant cut, it offers a unique, understated beauty that is highly valued in vintage and classic jewellery designs.

Single-Cut

A single-cut diamond refers to an old-style cut that features only 16 facets in total – 8 on the crown (the top portion of the diamond) and 8 on the pavilion (the lower portion). This style of diamond cutting is one of the earliest methods used in diamond cutting history and was prevalent before more advanced cuts like the brilliant cut became popular.

The single-cut diamonds were originally designed to make the most of the available diamond rough, often with the goal of enhancing the sparkle of small stones. The limited number of facets (compared to modern cuts) results in a simpler appearance, but they still display a degree of brilliance when well-cut.

Key Features of Single-Cut Diamonds:
Facets: The single-cut diamond typically has 16 facets – 8 on the crown and 8 on the pavilion, making it less complex than the round brilliant or emerald cut, which have far more facets.

Size and Sparkle: This style of cut is typically used for small diamonds. Despite the simpler facet structure, a well-cut single-cut diamond can still display sparkle, though it will not exhibit the intensity of light return seen in more modern cuts.

Historical Significance: The single cut was one of the first attempts at enhancing the natural sparkle of a diamond and was the preferred cut for small diamonds in vintage jewellery. It is still sometimes used today for very small diamonds (such as those used in mosaic or pavé settings), where a smaller, simpler cut is sufficient.

Modern Use: Although modern diamond cutting techniques now dominate, the single-cut remains relevant in certain instances, especially for tiny accent diamonds in vintage-inspired designs or budget-friendly pieces. This cut tends to be affordable due to the simplicity and fewer facets involved in the cutting process.

Appearance: The look of a single-cut diamond is generally less brilliant than a modern round brilliant cut, as it has fewer facets to interact with light. However, it still offers a certain charm, particularly in smaller sizes, where the increased facet count of larger stones may not be necessary.

Other Names:
The single-cut diamond is also referred to as an eight cut, which describes the eight facets on each side (crown and pavilion), emphasising its simplicity compared to the more complex, modern diamond cuts.

While not as commonly used for larger stones today, the single cut holds a place in history and is cherished in vintage and antique jewellery, often offering a nostalgic, traditional look for those seeking a more classic style.

Scintillation

Scintillation refers to the sparkle or twinkle that a diamond exhibits as light reflects off its surface when it is in motion. This effect creates a series of quickly shifting flashes of light, which are particularly noticeable when the diamond is moved. The dynamic movement of the stone causes light to be reflected in different directions, producing a visually captivating and lively display of brightness and colour. Scintillation is one of the key visual characteristics that contributes to a diamond’s overall allure and desirability, alongside other factors such as brilliance and fire.

Key Features of Scintillation
Definition of Scintillation:

Scintillation is the rapid, sparkling flashes of light that appear as a diamond is moved in different directions. This effect is created by the way light interacts with the diamond’s facets. The shifting nature of the scintillation is often described as “twinkling,” and it’s most noticeable when the diamond is moved or rotated in the light.
How Scintillation Occurs:

When a diamond is illuminated, light enters through its table (the flat top surface), is reflected off the facets (the flat surfaces of the diamond), and exits through the crown. The facets, depending on their size, shape, and angle, cause light to bounce and reflect off the diamond in a multitude of directions.
As the diamond is moved, the angles of reflection change, and the light flashes in varying positions, creating the scintillation effect. The more facets a diamond has, the more reflections can occur, leading to more noticeable scintillation.
Factors Influencing Scintillation: Several factors impact the intensity and quality of scintillation in a diamond:

Quality of Polish:
The polish of a diamond affects the smoothness of its surface. A well-polished diamond will have a smoother surface, allowing light to reflect more easily off the facets, creating a more intense scintillation effect. Poor polish can cause surface irregularities, leading to light scattering in less predictable ways and reducing the overall sparkle.

Facet Arrangement:
The way the facets are arranged also plays a role in the movement of light across the surface of the diamond. Symmetrical arrangements of facets allow for more consistent and structured reflections, leading to enhanced scintillation. Diamonds with asymmetrical or poorly aligned facets may not reflect light as effectively, reducing the intensity and consistency of the sparkle.

Size and Shape of the Diamond:
The size and shape of the diamond also influence the degree of scintillation. Larger diamonds have more surface area, which can produce more flashes of light. Additionally, diamonds with complex facet arrangements (like the round brilliant cut) tend to exhibit more scintillation due to the numerous facets designed to reflect light in different directions. Fancy-shaped diamonds, such as princess cut, emerald cut, and asscher cut, may also display scintillation, but it is influenced by their specific facet configurations.

Cut Quality:
The overall cut quality of a diamond is one of the most significant factors influencing scintillation. Diamonds that are cut to ideal proportions (as determined by standards such as the GIA or DCLA) will produce more sparkle, as light will be reflected more efficiently through the facets. Poorly cut diamonds, even with high colour or clarity, may lack the desired scintillation due to the misalignment of their facets or improper depth and table size.

Scintillation vs. Brilliance vs. Fire:

While brilliance refers to the amount of white light that is reflected from the diamond, and fire refers to the dispersion of coloured light (such as flashes of red, blue, and yellow), scintillation is more closely related to how dynamic and moving the light appears when the diamond is rotated. Together, these three factors—brilliance, fire, and scintillation—create the visual appeal that makes diamonds so captivating.

Brilliance: The total amount of white light reflected from the diamond’s surface, which can be influenced by the cut, the angle of the facets, and the overall design of the diamond.

Fire: The dispersion of light into different colours as it travels through the diamond, creating rainbow-like flashes.

Scintillation: The movement of light across the surface of the diamond, seen as quick flashes or twinkling when the diamond is in motion.

Types of Diamonds and Scintillation:

Round Brilliant Cut Diamonds: Known for their exceptional scintillation, round brilliant diamonds have a highly structured and symmetrical facet arrangement designed to maximise light reflection. Their large number of facets and symmetrical cuts create dynamic scintillation, making them one of the most sparkling diamond cuts.
Princess Cut Diamonds: With a square or rectangular shape, princess cut diamonds also exhibit good scintillation, but the sparkle can differ due to their unique facet arrangements. The sharp corners of the princess cut can sometimes create brilliant flashes that differ from the round brilliant’s consistent twinkling.
Emerald Cut Diamonds: While the emerald cut is known for its clarity and elegant appearance, it doesn’t showcase as much scintillation as round or princess cuts. Instead, it focuses more on transparency and clarity of the diamond. However, it can still exhibit scintillation under certain lighting conditions, although it is less pronounced.
Cushion Cut Diamonds: The cushion cut diamond combines brilliance with fire, and its larger facets can create noticeable scintillation. The more modern cushion cuts with extra facets will tend to have more scintillation than the older, traditional ones.
Visual Impact of Scintillation:

Scintillation is what makes a diamond feel alive, contributing to its dynamic beauty. The ever-changing flashes of light draw the eye, making the diamond appear to sparkle and move with the slightest tilt or turn. This effect is especially noticeable in well-lit environments, where light reflects off the facets to create an irresistible twinkling effect.
Diamonds with high scintillation are often perceived as more lively and captivating, as the sparkle makes the stone appear dynamic and full of energy. Scintillation is a quality that people naturally associate with luxury, elegance, and timeless beauty.
The Role of Scintillation in Diamond Selection:

For those selecting a diamond, scintillation can be an important factor to consider, particularly if the buyer is looking for a diamond that will create an impactful visual presence. Diamonds with higher scintillation will tend to stand out in light and movement, making them excellent choices for people who want their diamonds to have a noticeable sparkle.
Brilliant cuts, such as the round brilliant, are often selected for their ability to exhibit maximum scintillation. However, other shapes, such as the princess cut or oval cut, can still provide plenty of sparkle, though the effect may be slightly different.

Scintillation is a key feature of a diamond’s visual appeal, referring to the dynamic sparkle that occurs when light is reflected off the diamond’s facets during movement. This shimmering effect is dependent on factors such as the quality of the polish, the arrangement of facets, and the cut quality of the diamond. Diamonds with excellent scintillation create a lively, twinkling effect that enhances their beauty, making them incredibly captivating and desirable. Whether in a round brilliant, princess, or cushion cut, scintillation remains one of the primary aspects that make diamonds so visually stunning and prized.

Shape

Name for the basic outline of a polished diamond

In the context of diamonds, shape refers to the basic outline or form of a polished diamond, which is distinct from its cut (which pertains to the diamond’s facets, proportions, and overall craftsmanship). The shape is the fundamental, overall geometry of the diamond, determining its appearance and how it interacts with light. The shape of a diamond is typically selected based on personal preference, aesthetic taste, and desired brilliance, as different shapes have different effects on the way a diamond reflects light and sparkles.

Types of Diamond Shapes
There are several common diamond shapes, each with unique characteristics, and they vary in terms of their appearance, the way they reflect light, and their overall style. Below are some of the most popular diamond shapes:

Round:

The round shape is the most popular and traditional diamond shape, known for its exceptional brilliance and sparkle. It has a circular outline and is cut with 57 or 58 facets, including the table, crown, pavilion, and girdle. This shape maximises light reflection, making it the most sought-after shape for engagement rings and other jewellery.
The round shape is also known as the round brilliant cut, which is designed to achieve the highest level of brilliance and scintillation, making it the benchmark for diamond cutting.
Princess:

The princess shape is a square or rectangular diamond with pointed corners. It is the second most popular diamond shape after the round shape and is prized for its sharp, modern appearance. Princess cut diamonds have a brilliant faceting style, offering excellent sparkle. This shape is often selected for engagement rings and other jewellery due to its versatile and elegant appearance.
This shape is known for its clean lines, and it’s often favoured by those who want the brilliance of a round diamond but prefer a more angular look.
Emerald:

The emerald shape is a rectangular diamond with cut corners and a step-cut faceting style. Unlike the brilliant cuts, emerald cut diamonds are more about clarity and the stone’s internal characteristics, showcasing the diamond’s clarity through large, open facets.
The emerald shape is known for its elegance, producing a sleek and sophisticated look. It is particularly suited for those who appreciate a vintage style or want a more subtle, understated sparkle compared to the brilliance of other cuts.
Cushion:

The cushion shape is a square or rectangular diamond with rounded corners, giving it a pillow-like appearance. This shape combines features of both the round brilliant and emerald cut, offering a balance of brilliance and clarity.
The cushion shape has a romantic, vintage appeal and is known for its soft, gentle curves. This shape has become increasingly popular in recent years, especially in antique-style jewellery.
Oval:

The oval shape is an elongated round diamond, offering the same brilliance as a round diamond but with an elongated, oval outline. This shape creates the illusion of a larger stone due to its elongated shape and is often chosen for its ability to make fingers appear more slender.
Oval diamonds are known for their classic elegance and sparkling appearance. The elongated form gives a sense of modernity, and it works well in many jewellery settings, particularly for engagement rings.
Marquise:

The marquise shape is a football-like or boat-shaped diamond, with pointed ends and a long, elongated outline. This shape is known for creating the illusion of length and size, making it appear larger than other shapes of the same carat weight.
Marquise diamonds are ideal for creating a bold, dramatic look and are often used in statement pieces or vintage-inspired designs.
Pear:

The pear shape is a combination of round and marquise cuts, with one pointed end and one rounded end, resembling a teardrop. This shape has a soft, elegant look and is often seen in pendants, earrings, and engagement rings.
The pear shape is known for its flattering effect on the hand or neck, as its elongated shape can make the fingers or neckline appear more slender. It also offers a unique balance of brilliance and elegance.
Asscher:

The asscher shape is a square version of the emerald cut, with cut corners and a distinctive step-cut faceting. This shape has a vintage appeal, often associated with the early 20th century and the art deco period.
The asscher shape is known for its regal, sophisticated look and clarity, emphasising the diamond’s natural beauty and internal characteristics. It’s a great choice for those who enjoy vintage or retro styles.
Radiant:

The radiant shape is a square or rectangular diamond with cut corners, combining the brilliance of a round cut with the elegance of an emerald cut. The facets of a radiant diamond are typically more brilliant, giving the stone a striking sparkle while retaining its structured outline.
Radiant diamonds are popular for their modern appeal and versatility, working well in many types of jewellery, from engagement rings to statement necklaces.
Heart:

The heart shape is a romantic, symbolic diamond shape, resembling a heart. It’s a modified brilliant cut, and it’s often selected for engagement rings and valentine’s jewellery due to its emotional significance.
Heart-shaped diamonds combine both brilliance and emotional appeal, and they are often used in pendants, rings, and earrings for special occasions.
Factors Influencing Diamond Shape Selection
When choosing a diamond shape, several factors should be considered:

Personal Taste: The aesthetic preference of the buyer plays a crucial role in selecting the shape. Some may prefer the classic brilliance of the round shape, while others may gravitate towards the elegance of the emerald or the romance of the heart.

Brilliance: Different shapes have varying levels of brilliance. Round diamonds generally offer the highest level of brilliance, while step-cut diamonds (like emerald and asscher) may offer less sparkle but more emphasis on clarity.

Finger Shape and Size: Some diamond shapes, like the oval and marquise, can make fingers appear longer and slender, while other shapes, like cushion or round, may have a more balanced look.

Diamond Setting: The shape of the diamond affects the type of setting it can be used with. Round diamonds fit most settings, but fancy-shaped diamonds, like pear or heart, may require more custom settings to highlight their unique outlines.

Size Appearance: Some diamond shapes, like marquise and pear, can create the illusion of a larger diamond, which may be preferred for those looking for a bigger appearance without increasing carat weight.

The shape of a diamond is a fundamental factor in its overall appearance and appeal. Each shape offers its own unique style, brilliance, and aesthetic qualities, allowing buyers to select the diamond that best reflects their personal tastes, lifestyle, and the intended jewellery setting. Whether opting for the timeless round or the elegant emerald, each shape offers something special, making it an essential element in choosing the perfect diamond.

Rough Diamond

A rough diamond is a diamond in its natural state, exactly as it is found deep within the Earth. It has not yet undergone any form of cutting, polishing, or alteration. Rough diamonds are typically irregular in shape, with a variety of textures, colours, and surface conditions, ranging from clear and transparent to opaque and coloured.

These diamonds are generally discovered in kimberlite pipes (volcanic formations) or alluvial deposits (water-worn areas), and they are extracted through a process of mining. Once found, rough diamonds are carefully sorted and graded based on their size, shape, colour, and clarity before they are sent to gem cutters for transformation into polished stones.

Key Characteristics of Rough Diamonds
Shape:

Rough diamonds are typically irregular, with shapes that can range from octahedral (two pyramidal shapes joined together) to dodecahedral (a 12-sided form). These shapes are determined by the crystal structure of the diamond and can vary widely.
The rough shape is not intended for jewellery, and the gem cutters will plan how to cut the stone based on its natural geometry to maximise yield and minimise waste.
Colour:

Rough diamonds can appear in a wide range of colours, from colourless and transparent to shades of yellow, brown, or even rare colours such as blue, green, or pink.
The final colour of the diamond will depend on its internal structure and any trace elements present in the rough material. Some rough diamonds are even tinted due to the presence of minerals or impurities.
Clarity:

In their natural form, rough diamonds may have a variety of inclusions and blemishes, such as tiny air bubbles or mineral inclusions trapped within the crystal. These internal flaws are often visible to the naked eye or under magnification, though they can be reduced or eliminated during the cutting and polishing processes.
Size:

Rough diamonds vary greatly in size, from small pebbles to large stones weighing several carats. Larger rough diamonds are often considered more valuable, especially if they possess good colour and clarity, as they can be cut into high-quality finished diamonds.
The Journey of a Rough Diamond
Extraction:

Rough diamonds are mined from the Earth, typically through open-pit mining, underground mining, or alluvial mining (searching for diamonds in riverbeds or coastal regions). Mining companies extract the rough stones from kimberlite pipes or riverbeds, often using advanced technology to locate diamond deposits deep underground.
Sorting and Grading:

Once extracted, rough diamonds are sorted based on their size, colour, clarity, and shape. Each diamond is examined to determine its potential for cutting and polishing. Some rough diamonds are too flawed or small to be cut into gem-quality stones and may be used for industrial purposes instead.
The DCLA (Diamond Certification Laboratory of Australia) offers rough diamond services to help classify and grade rough diamonds. They use their expertise to evaluate the quality of rough diamonds and assist in planning the best course of action for cutting and polishing.
Cutting and Polishing:

After sorting, the rough diamond is sent to skilled gem cutters, who use advanced techniques and tools to transform the stone into its finished form. The cutting process involves careful planning to maximise the yield (the amount of diamond produced from the rough stone) while aiming to enhance the diamond’s brilliance, fire, and overall appearance.
The diamond may be cut into a variety of shapes, such as round, emerald, princess, or cushion, depending on the rough stone’s shape and quality.
Grading:

Once the diamond is cut and polished, it is then graded according to the 4 Cs – Carat, Colour, Clarity, and Cut. This grade determines the diamond’s final value, and certificates from recognised laboratories such as DCLA are used to authenticate the quality of the diamond.
Uses of Rough Diamonds
Gem-quality Diamonds:

The primary use of rough diamonds is for gemstone production, where they are cut and polished into diamonds for use in engagement rings, earrings, necklaces, and other high-end jewellery.
Industrial Diamonds:

Some rough diamonds, particularly those with significant imperfections, are not suitable for use in jewellery. These diamonds are used for industrial purposes, where their hardness is highly valued. Industrial diamonds are employed in applications such as cutting, grinding, drilling, and polishing, where the diamond’s extreme hardness makes it ideal for cutting or shaping other materials.

The rough diamond is the very first step in the life cycle of a diamond. Found in the earth in its natural form, it is then extracted, sorted, and carefully crafted into the sparkling gemstones that are valued in fine jewellery. Due to their rarity and the complexity of their transformation, rough diamonds represent both the mystery of nature and the skill of the craftsmen who shape them into stunning finished products.

Round Brilliant Cut

Round Brilliant Cut Diamond cut or shaped into a circular outline or circumference

The Round Brilliant Cut is by far the most popular and widely recognised diamond cut, known for its ability to showcase a diamond’s brilliance, fire, and scintillation. It is designed to maximise the diamond’s reflective qualities and ensure that the stone sparkles to its fullest potential. The cut is characterised by its circular outline and cone-shaped pavilion, with a set number of facets that are precisely arranged to enhance the light performance of the diamond.

Key Features of the Round Brilliant Cut
Shape and Outline:

As the name suggests, the round brilliant cut is defined by its circular shape, which makes it instantly recognisable. This symmetrical shape enhances the light return, which is one of the key factors that contributes to the diamond’s brilliance. The round shape also provides a classic aesthetic, making it a timeless choice for engagement rings and other fine jewellery.
Facets:

The standard round brilliant cut typically has 57 facets, though some stones may have 58 facets if the culet (the small flat facet at the bottom of the diamond) is also included. These facets are carefully cut to reflect and refract light, creating the characteristic sparkle and fire that makes the round brilliant cut so desirable.
The facets of a round brilliant diamond are divided into three main sections: the crown, girdle, and pavilion:
Crown: The upper portion of the diamond, which includes the table (the flat top surface) and the facets that radiate from it.
Pavilion: The lower portion, which is cone-shaped and holds the majority of the diamond’s facets.
Girdle: The thin band around the diamond that separates the crown from the pavilion.
Brilliance, Fire, and Scintillation:

The brilliance of a round brilliant cut diamond refers to its white light reflection, or how much light the diamond returns to the eye. The angles and arrangement of the facets are designed to allow light to enter through the table, reflect off the internal surfaces, and return through the top of the diamond, creating that dazzling sparkle.
Fire refers to the flashes of coloured light that appear as the diamond moves. The number of facets in a round brilliant cut maximises the dispersion of light, creating vibrant flashes of red, blue, and yellow as the stone is rotated.
Scintillation is the term for the sparkle or twinkle of the diamond as it moves. A round brilliant cut diamond will exhibit high scintillation, meaning that it produces continuous flashes of light with every slight motion.
Cut Quality:

The cut quality of a round brilliant diamond is one of the most important factors influencing its overall beauty. The proportions of the diamond, including the table size, crown angle, pavilion depth, and girdle thickness, all play a crucial role in how well the diamond performs with light.
A well-cut diamond will have a perfect balance between brilliance, fire, and scintillation, with all the facets working together to maximise the diamond’s light return.
Diamonds with poor proportions will leak light, reducing the brilliance and fire of the stone, and making the diamond appear duller.
Round Brilliant Cut vs Other Cuts
The round brilliant cut is the most commonly chosen diamond shape, largely because it offers the best overall light performance. However, there are other shapes and cuts, each with their own appeal:

Cut Shape Facets Light Performance Appeal
Round Brilliant Circular 57 or 58 Exceptional brilliance, fire, scintillation Timeless, classic, maximum sparkle, highly popular
Princess Cut Square or Rectangular 57 Excellent brilliance, good scintillation Modern, sharp, distinctive, highly popular
Emerald Cut Rectangular 58 Moderate brilliance, strong clarity and transparency Elegant, sophisticated, highlights clarity
Cushion Cut Square with rounded corners 58 Good brilliance, antique-like appeal Romantic, vintage-inspired, soft sparkle
Oval Cut Oval 58 Similar to round, slightly elongated brilliance Unique, elegant, elongates the finger
Asscher Cut Square 58 Exceptional clarity, vintage look Art Deco style, striking clarity, bold aesthetic
Marquise Cut Boat-shaped 58 High brilliance, elongates appearance Dramatic, elegant, optimises carat weight
Advantages of the Round Brilliant Cut
Maximum Brilliance:

The round brilliant cut is specifically designed to maximise the brilliance of a diamond. The precise facet arrangement and angles ensure that the diamond performs optimally in terms of light reflection and refraction, resulting in a highly sparkling stone.
Timeless and Classic:

The round brilliant cut is a timeless design, and its classic appeal makes it one of the most popular choices for engagement rings and other fine jewellery. Its symmetrical shape is universally appealing, and it remains a symbol of elegance and refinement.
Versatility:

A round brilliant cut diamond can complement a wide variety of settings, from solitaire rings to halo settings or more intricate designs. The shape’s versatility means it suits both traditional and modern jewellery styles, making it a versatile choice for all types of jewellery.
Resale Value:

Round brilliant cut diamonds tend to hold their value well in the market. Due to their popularity and high demand, they are often considered a good investment choice, with strong resale value.
Considerations When Choosing a Round Brilliant Cut
Cut Quality:

The cut of a round brilliant diamond is one of the most important factors in determining its overall appearance. It’s essential to consider the diamond’s proportions, as a well-cut stone will showcase the best light performance. Always ensure that the diamond has been graded by a reputable lab, such as the GIA or DCLA, to ensure the cut is of high quality.
Budget:

Round brilliant cut diamonds are often priced at a premium due to their popularity and demand. While they offer exceptional beauty, it’s important to set a budget that aligns with your preferences and financial considerations. Smaller diamonds or diamonds with lower colour or clarity grades may be more affordable, while larger, higher-quality stones will command a higher price.
Carat Size:

The size of the round brilliant cut diamond also impacts its value. Larger stones typically cost more, and their brilliance is even more pronounced due to the increased surface area. However, even smaller round brilliant diamonds can deliver incredible sparkle and beauty when cut well.

The round brilliant cut remains the most popular and sought-after diamond shape due to its exceptional brilliance, sparkle, and timeless appeal. Its carefully planned facet arrangement ensures optimal light performance, creating a diamond that dazzles with every movement. Whether as an engagement ring, a pendant, or earrings, the round brilliant cut continues to captivate and delight, making it the perfect choice for anyone seeking a diamond with unmatched brilliance and elegance.