Diamond Shapes and Cuts

Diamond “Cut” Shapes

 What types of Diamond Cut Shapes are there?

Well there are two main types of diamond  shapes that are cut.

The first is the brilliant cut and the second is step cut.


The first, brilliant cut has a big advantage as it is not as necessary to choose such a high grade of stone as the brilliance of the cut can easily cover most small inclusions.

When purchasing a step cut diamond it’s always best to choose a higher quality stone as the inclusions are easier to see due to the nature of the cut.

Brilliant cut diamonds are usually supplied in the following shapes:

 Round, Oval, Marquise, Radiant, Princess, Pear, Cushion and Heart shape.

Step Cut diamonds are supplied in the following shapes:

 Emerald cut and Asscher cut.

Although the diamond shapes listed above are what they are known as to the general public, the diamond laboratories sometimes call them different names such as Square Modified Brilliant for the Princess Cut and Square Emerald Cut for Asscher Cut and so on.

This is because some of these names are the branded names given to certain diamond shapes and the diamond laboratories are not permitted to print these names on the certificates.

If you’re looking for a shape that’s not listed above, please call Jewellery by William.com on 08455190097 to discuss any of your requirements.

Diamond Ratios, Table% and Depth%

 Diamond ratios are very important.

A ratio is the measure of how square or rectangular a diamond is.


The only diamond in which the length to width ratio is not important is for obvious reasons the round brilliant diamond.

For all the other shapes, it’s very important, because the ratio of a diamond affects its beauty.

To get the ratio of any diamond just divide the length by the width.

Here are the recommended ratios, table% and depth% for the diamond shapes.

Recommended Diamond Ratio Criteria

Shape Length to Width Ratio Table % Depth %
Round Brilliant N/A 55% – 60% 59% – 62.5%
Princess Cut 1 to 1:03 64% – 75% 64% – 74%
Emerald Cut 1.30 to 1.46 58% – 73% 65% – 74%
Oval Cut 1.35 to 1.50 54% – 65% 58% – 68%
Pear Shape 1.38 to 1.55 50% – 60% 58% – 68%
Radiant Cut 1 to 1.15 50% – 60% 58% – 68%
Heart Shape 1 to 1.05 50% – 60% 58% – 68%
Marquise Shape 1.80 to 2.15 50% – 60% 58% – 68%
Cushion Cut 1 to 1.15 50% – 60% 58% – 68%
Asscher Cut 1 to 1.04 50% – 60% 58% – 68%