While often used interchangeably, a diamond’s cut and shape are two different things. Cut is a measurement of quality and diamonds are given grades ranging from poor to excellent. The shape of a diamond is a matter of personal preference and refers to the general silhouette of it when viewed face up.
What is a Diamond Cut?
A diamond’s cut is probably the most important of the 4 C’s (cut, clarity, color, carat) used to grade a diamond because it refers to how well its facets interact with light which results in its level of sparkle. In a well-cut diamond, light enters through the top, or table, and reflects off the angles between the flat places (the facets) on the sides (known as the crown and the pavilion) and exits back out the top.
All of that light bouncing around within the diamond creates its brilliance, fire and scintillation. Brilliance is the brightness created by a combination of white light reflections on and in the diamond and fire are the flashes of color you see within a diamond. Scintillation is the sparkle that happens when a diamond or light source moves. More than anything else, the quality of the cut determines a diamond’s overall beauty and dazzle.
Diamonds are cut into shapes with numerous facets, each acting like a mirror reflecting light from one part of the diamond to another. The more facets a stone has been cut with, the more brilliant and sparkly it will be. If you choose a cut with less facets, then other characteristics of the stone like clarity and color will be important. A diamond’s cut may also refer to the technique used to cut or form its facets.
- Brilliant cut creates a pattern for the maximum light return through the top of the diamond. This usually refers to the classic round diamond shape. The modern brilliant cut has 57 facets.
- Modified brilliant cut refers to other shapes cut in the same pattern as the round brilliant and includes: oval, pear, marquise, and heart. Since they’re all cut in the same pattern as round, they’re very close in brilliance.
- Step cut has “steps” running down the sides and on the top with a large open window on top that’s like peering into a hall of mirrors. This cut isn’t as sparkly and includes emerald and asscher.
- Mixed cut usually combines the pattern of a brilliant on top and a step cut on the bottom. Princess, cushion and radiant diamonds are mixed cuts.
- Rose cut is a vintage cut with a flat bottom and a domed top. Face up, it looks like a rose bud and is not known for brilliance.
What is a Diamond Shape?
The shape of a diamond refers to its geometric characteristics and general silhouette when viewed face up. Diamonds come in a variety of shapes, the most popular being round. There are two major groups of shapes: round and fancy which includes any shape that isn’t round.
The 12 most popular diamond shapes are:
- Round diamonds exhibit the most brilliance making them the most popular shape
- Princess are shaped like inverted pyramids and are the second most brilliant
- Cushion are square or rectangular with gently rounded corners
- Emerald are rectangular with carefully measured steps cut into their sides
- Marquise its distinctive silhouette is marked by curved sides and pointed ends
- Oval an elongated version of a round diamond
- Radiant mimics an emerald shape with deep-cut facets for extra sparkle
- Pear a tear-drop shape with evenly rounded end that fades into a point
- Asscher distinct step facets and large table deliver classy flashes of light
- Heart diamonds are cut into a heart shape
- Baguette a long, rectangular shape with 14 facets usually used on accent stones
- Trillion a triangular shape with either rounded or pointed edges and a shallow cut