Anyone exploring diamonds quickly encounters a wide variety of shapes. Beyond the classic round brilliant cut, there are numerous so-called fancy cuts – shapes that differ from the round form. Each shape carries its own optical and technical characteristics.
The Round Brilliant Cut
The round brilliant is the most common diamond shape. It typically consists of 57 or 58 facets and is optimized for maximum light reflection. This shape has been mathematically refined for over a century and serves as a reference point for many quality assessments.
Overview of Fancy Cuts
Common fancy cuts include:
- Oval – an elongated shape with light behavior similar to the round brilliant
- Cushion – a square or rectangular shape with rounded corners
- Emerald Cut – a rectangular step cut with clean lines
- Pear – a combination of rounded and pointed ends
- Princess – a square shape with sharp corners
Each of these shapes places different demands on the cutting process and the rough diamond used.
Impact on Light Behavior and Proportions
A diamond's shape significantly determines how light is reflected and refracted within the stone. Step cuts like the emerald cut produce a calmer, mirror-like appearance, while brilliant cuts such as round or oval are known for a sparkling look. Proportions – the ratio of length to width – also play a role in evaluating a shape.
Market Availability
Not every shape is equally available. Round brilliants continue to make up the largest share of the market, as they can often be cut more efficiently from rough diamonds. Fancy cuts frequently require a more individual assessment of the rough stone, which can affect availability and selection.
STIG GROUP and Diamond Shapes
At STIG INTERNATIONAL, diamonds of various shapes are documented and classified based on their GIA certification. Within STIG ROCK, allocation follows a structured and traceable process – independent of the specific cut shape of the stone.