The Four Cs: Cut, Carat, Colour and Clarity
The four Cs – cut, carat, colour and clarity – are the most widely recognised criteria for assessing a diamond's quality and value. While each plays an important role, they do not tell the whole story.
A certificate issued by a gemmological laboratory documents a diamond's characteristics, but its beauty cannot be determined by grades alone. Subtle variations exist within each grade, meaning that two diamonds with seemingly identical specifications can look noticeably different when viewed side by side.
This is why we believe a diamond should be appreciated in person, rather than judged solely by the information on its certificate.
How to Choose the Right Diamond
Choosing a diamond is a personal decision, and there is no single combination of qualities that suits everyone. The right choice depends on what you value most, whether that is size, colour, clarity or the way a diamond captures and reflects light.
Some are drawn to larger diamonds and prefer to prioritise carat weight over the highest colour or clarity grades. Others appreciate the warmth of a slightly tinted stone, while some favour diamonds that appear as colourless as possible. Understanding these differences, and knowing where they matter most, is an important part of finding the right diamond.
At Langaard, we take the time to understand what you are looking for. Drawing on our experience and specialist knowledge, we help you explore the qualities that matter to you and make informed choices within your budget.
A certificate provides valuable information, but it cannot fully convey a diamond's appearance. Its brilliance, proportions and response to light are best appreciated in person. We therefore encourage you to compare several diamonds side by side, where even stones with similar grades can reveal noticeable differences.
For individual guidance, we invite you to book an appointment with our gemmologist. Together, you can examine different diamonds, discuss their characteristics and gain a clearer understanding of how each quality factor influences their appearance and value.
Whether you are choosing a diamond for an engagement ring, a special occasion or a piece of jewellery to enjoy for years to come, the most important thing is finding a stone whose beauty you appreciate every time you wear it.
Carat
Carat refers to a diamond's weight rather than its physical size. One carat is equivalent to 0.20 grams.
The relationship between carat weight and price is not linear. Larger diamonds are generally rarer, which means that a 2.00 ct diamond can cost considerably more than twice as much as a 1.00 ct diamond of comparable quality.
Carat weight alone does not determine how large a diamond appears. Two diamonds of equal weight can have different dimensions depending on their cut and proportions. Factors such as diameter and depth influence how much of the diamond is visible when viewed from above.
Certain carat weights are particularly sought after in the diamond market. Often referred to as magic sizes, these include 1.00 ct, 1.50 ct and 2.00 ct. Diamonds that reach these thresholds can command a noticeable price premium over stones weighing just below them, even when the difference in size is barely perceptible.
When choosing a diamond, it is therefore important to consider carat weight alongside its cut, proportions and overall appearance.
Cut
The quality of a diamond's cut is one of the most important factors in its appearance. It influences how light interacts with the stone, affecting its brilliance, fire and sparkle. Even a diamond with excellent colour and clarity can appear lifeless if it is poorly cut.
Cut quality is determined by the diamond's proportions and how effectively they allow light to return to the eye. When a diamond is well proportioned, light entering the stone is reflected and refracted in ways that enhance its brightness and brilliance. Symmetry and polish also contribute to the overall quality of the finish.
Cut quality is commonly assessed on a scale from Excellent to Poor, with Excellent representing the highest grade. This grading system is used by laboratories such as the GIA for round brilliant diamonds. A poorly proportioned diamond, by contrast, may allow more light to escape through its sides or bottom, reducing its brilliance.
At Langaard, we encourage you to pay particular attention to cut when choosing a diamond. The quality of the cut can have a greater influence on a diamond's beauty than a small difference in colour or clarity grade.
Diamond Shapes
The round brilliant is the most popular diamond shape, prized for its exceptional brilliance and sparkle. Its carefully arranged facets are designed to maximise the way light is reflected and returned to the eye.
Other popular diamond shapes include:
• Oval
• Cushion
• Princess
• Emerald
• Pear
Each shape has its own distinctive appearance. Elongated shapes, such as oval and pear, can appear larger than round diamonds of the same carat weight, depending on their proportions. Their shape can also create a flattering, lengthening effect when worn in a ring.
The arrangement of a diamond's facets also influences how visible its inclusions may be. Step-cut diamonds, such as the emerald cut, have broad, open facets that can make inclusions easier to see. Brilliant-cut diamonds, by contrast, often have more intricate facet patterns that can make certain inclusions less noticeable.
This is why we recommend considering each diamond as a whole. Shape, cut, colour and clarity all contribute to its appearance, and the right balance will depend on the individual stone and
Colour
Most natural diamonds have subtle traces of colour, typically yellow or brown. Diamonds that appear completely colourless are exceptionally rare and are generally more valuable. Even slight variations in colour can influence a diamond's appearance and price.
The Gemological Institute of America (GIA) uses an internationally recognised colour grading scale, ranging from D to Z. Diamonds graded D are considered colourless, while those towards the lower end of the scale display increasingly noticeable yellow or brown tones.
D – Colourless
Z – Light yellow or brown
Traditional trade terms are also sometimes used to describe different colour grades:
River – D–E
Top Wesselton – F–G
Wesselton – H
Choosing the Metal
The choice of metal can influence how a diamond's colour is perceived. White gold and platinum provide a cool, neutral setting that works particularly well with diamonds in the higher colour grades, allowing their colourless appearance to take centre stage.
Diamonds with warmer yellow or brown undertones can be beautifully complemented by yellow or rose gold. The warmth of the metal can soften the contrast between the setting and the stone, making subtle traces of colour less noticeable.
A diamond's size and cut also affect how its colour appears. Warmer tones may be more noticeable in larger diamonds, while cuts with broad, open facets, such as the emerald cut, can reveal colour more readily than brilliant cuts with more intricate facet patterns.
Champagne Diamonds
Champagne diamonds are distinguished by their warm, natural hues, ranging from delicate champagne tones to rich cognac shades. Their distinctive colouring is particularly well suited to yellow and rose gold, where the warmth of the metal complements the diamond's natural character.
Compared with colourless diamonds of similar size and quality, champagne diamonds are often more accessible in price. This can offer greater flexibility when choosing a diamond, whether the priority is a larger stone or a particular depth of colour.
Black Diamonds
Black diamonds are distinguished by their deep, opaque appearance. In naturally black diamonds, the colour is often caused by a high concentration of inclusions, particularly graphite and other dark minerals. Many black diamonds available today have also been treated to achieve a deeper, more uniform colour.
Unlike colourless diamonds, black diamonds do not transmit light in the same way. Rather than displaying the brilliance and fire associated with transparent diamonds, their polished surfaces reflect light, creating a distinctive lustre.
Their intense colour offers a striking contrast when set against precious metals or paired with colourless diamonds, making them an interesting choice for jewellery where shape, texture and contrast take centre stage.
Naturally Coloured Diamonds
Beyond the traditional D–Z colour scale are natural fancy-colour diamonds, among the rarest gemstones in the world. These diamonds occur in a remarkable range of colours, including yellow, pink, blue, green and red.
Their value is influenced by several factors, with the rarity, intensity and distribution of colour playing a particularly important role. Certain hues, especially vivid pinks, blues and reds, are exceptionally scarce. Larger diamonds displaying these colours are rarer still, with outstanding examples occasionally appearing at major international auctions.
Clarity
Clarity describes the natural inclusions and internal characteristics found within a diamond. Almost every natural diamond carries traces of the conditions in which it was formed deep within the Earth. These can include tiny mineral inclusions, growth patterns and small fractures. Diamonds entirely free from inclusions and surface blemishes are exceptionally rare.
When a diamond is graded for clarity, the number, size, nature, position and visibility of its inclusions and blemishes are all taken into account. The GIA clarity scale ranges from FL (Flawless) to I3 (Included).
In diamonds graded SI1 or higher, inclusions are often not visible to the naked eye. However, this varies from stone to stone, which is why we recommend examining the diamond itself rather than relying on its clarity grade alone.
At Langaard, we do not necessarily regard natural inclusions as imperfections. They are part of the diamond's formation and contribute to the individual character of each stone. What matters is where the inclusions are located, how visible they are and whether they affect the beauty or durability of the diamond.
Some inclusions require closer consideration. Fractures that reach the surface or extend towards vulnerable areas of the diamond can, depending on their size and position, affect its durability. This is particularly important for jewellery such as rings and bracelets, which are more exposed to knocks and everyday wear.
The Kimberley Process
Established in 2003, the Kimberley Process Certification Scheme (KPCS) is an international initiative designed to prevent conflict diamonds from entering the legitimate diamond trade. It sets requirements for the certification and cross-border trade of rough diamonds, with participating countries accounting for the vast majority of global rough diamond production.
The scheme plays an important role in promoting transparency and accountability within the diamond industry. While its scope is specifically focused on preventing the trade in conflict diamonds, it remains an important part of wider efforts to encourage responsible sourcing.
At Langaard, we work exclusively with established, reputable suppliers who comply with the requirements of the Kimberley Process and applicable international standards for responsible diamond sourcing.
