Anatomy of a Diamond

The Evolution of the Brilliant Round Cut Diamond

Have you ever heard someone referred to as a “diamond in the rough?” It's actually a compliment. Rough, or “natural” diamonds are stones which haven't yet been subjected to extraction, cutting, polishing and grading. In their humble form, they have no intrinsic value per se and resemble little more than lumps of glittering rock, often amalgamated with various other semi-precious minerals. Once diamond ore has been extracted, it is first cleaned and inspected for any major flaws or cracks before it is scanned by computer or studied by a Master Planner to determine optimal cutting points. Cut is one of the primary characteristics taken into consideration during diamond grading, a method employed throughout the jewellery industry to gauge the quality and value of diamonds. 

The diamond cutting method has evolved significantly over the last 700 years, and people have developed from being able to cut only the basic simple Point Cut that basically follows the original octahedral shape of the rough stone, to the modern Brilliant cut that uses dozens of well positioned and angled facets to bring out its utmost brilliance and fire. The inception of diamond saws and jewellery lathes circa 1900 heralded a significant change in traditional cutting techniques, paving the way for many style variations, including the Round Brilliant cut. Belgian diamond-cutter Marcel Tolkowsky analysed the anatomy of the cut in 1919 with the aim of developing his own signature cut. During his analysis, Tolkowsky calculated the efficacy of the cut for both brilliance (the degree of white light reflected by the stone) and fire given off. The results of his study would serve as the basis for all future modifications to, and variations of the Round Brilliant cut. 

The table below timelines the evolution of the Round Brilliant cut during the course of the last 700 years:

Understanding the Anatomy of a Diamond

There are various terminologies used in the jewellery industry to describe certain aspects and facets of a diamond. Traditional round cut brilliant diamonds are characterised by 57-58 facets depending upon the presence of a culet (the small facet sometimes cut into the base of the pavilion). 

Below are some of the most common terminologies used to refer to different areas of a diamond's physical anatomy:

•Table: refers to the flat facet on the top surface of the diamond, and is also usually the largest.

•Crown: often used to describe the upper body of the diamond above the girdle. The crown encompasses both the flat table facet, and the depth of two facets to the girdle. 

•Girdle: marks the widest part of the diamond, or the outer circumference forming a band around the stone. Not all girdles are uniform in appearance; some may be frosted, polished smooth, or faceted. 

•Pavillion: the lower body of the diamond below the girdle.

•Culet: a very small, flat facet sometimes added by cutters to the base of the diamond pavillion to avoid it being chipped or cracked when set in jewellery. Usually when a diamond is set in a piece of jewellery, the setting itself is usually of sufficient depth and quality to accommodate the pavillion and protect it from chipping or damage. 

•Depth: is the measurement of a diamond from the culet to the table facet in millimetres. 

•Crown angle: defines the angle where the bezel facets conjoin the girdle at the widest point. The series of facets along the crown angle are largely responsible for the dispersion of light and spectral colours from within the diamond. A slightly steeper crown angle can also influence the aesthetic brilliance and fire given off by the diamond. 

•Diameter: the diamond's circumference measurement taken at the widest point of the girdle. 

Common Diamond Cuts and Shapes

To most people, diamonds are circular gems of uniform cut and facet number that equate to a dazzling appearance. True, many diamonds are produced in the traditional Round Brilliant format, however, they are also available in fancier cuts and shapes to appeal to modern markets. From the timeless Round Brilliant cut, to more unusual 'fancy' shapes such as the Pear and square Princess cuts, there are variations to suit just about every personal taste. 

•Round Brilliant: This is the most popular of all diamond shapes, and accounts for more than 80% of diamonds retailed today. Round Brilliant diamonds comprise 57-58 facets (depending upon the presence of a culet) distributed above the pavilion, and below the crown. They are usually of uniform shape and symmetry; manufactured to an exacting standard  that guarantees maximum brilliance, fire and scintillation. 

•Cushion: The Cushion cut (also known as the pillow-cut) derives from the Old Mine cut, popular during the 19th Century. Slightly elongated with rounded corners, it is modernly considered a variation on the oval, despite being over 100 years old. Prior to the Millennium, it was almost impossible to find Cushion cut diamonds outside of specialist auctions, however, the shape is once again finding favour among young couples for wedding and engagement rings. 

•Brilliant Cut Oval: The Oval cut is relatively younger than its counterparts, created during the 1960's by none other than Marcel Tolkowsky's cousin, Lazare Kaplan. An elliptical twist on the traditional Round Brilliant, the elongated oval is revered for its fiery brilliance, making it an extremely popular shape for fashion jewellery. 

•Marquise: An antique elongated cut, characterised by a wide body and pointed ends, the Marquise cut is a popular choice for solitaire rings. Legend has it that the cut was inspired by the Marquise de Pompadour; French king Louis XIV being so captivated by her, he commissioned this cut, just so he could have a constant reminder of her smile. 

•Pear: The Pear cut is regarded a hybrid of the traditional Round Brilliant and the Marquise, characterised by a distinctive tear-drop shape and exceptional brilliance. Pear-shaped diamonds are commonly found inset in larger items of jewellery, such as pendants, because it was extremely difficult to achieve perfect symmetry with smaller stones. 

•Heart: Rare, yet sophisticated, the Heart cut is widely considered the most romantic of diamond cuts, yet also one requiring exceptional skill. Like the Pear, this modern cut must be equally proportionate to avoid any impact on aesthetic brilliance – of significant importance given its popularity as a Valentine's gift!

•Emerald: With stepped sides and slightly curved corners, the Emerald cut is love by many.  The elegant Emerald cut diamonds have a robust structure and tend to be more popular for reproduction antique and fashion jewellery.

•Princess: Second only to the Round Brilliant cut in popularity, the square Princess cut is a prime choice for anyone who wants a cut that is both clean, and contemporary. This relatively modern hybrid was  conceived in the 1960's; the result of several tried and failed attempts at producing a square cut that replicated the fire and brilliance of a traditional Round Brilliant diamond. Princess cut diamonds will usually have additional 'chevrons' cut into the facets around the crown. This allows far more light to be reflected and refracted by the diamond, thus increasing its brilliance. 

•Radiant: This relatively new take on the traditional Asscher cut is quite similar to the Princess for brilliance and fire, however, usually takes the form of a rectangle with clipped or cut corners. With a greater number of facets than the old Asscher cut, the Radiant cut is often utilized for darker Fancy Diamonds to accentuate their colour.

•Asscher: Characterised by stepped edges, cropped corners and graduating squares, the antique Asscher cut was an extremely fashion-forward style given that it was developed in 1902. Often known as the “Square Emerald” cut, this Art Deco design was created with the primary intention of drawing the eye into the diamond. Despite its contemporary aesthetic, the Asscher cut was all but forgotten until it featured on the hit American TV series “Sex and the City”. 

If you are interested in purchasing one of the Fancy Diamond shapes outlined above, please contact one the friendly consultants at England Diamond who will be more than happy to assist you.