Diamond vs Brilliant: What Is the Difference?

Short answer: “Diamond” is the name of the stone; a “brilliant” is a diamond cut with a special 57-facet cut. So every brilliant is a diamond, but not every diamond is a brilliant. In Turkish jewellery shops, the word “elmas” (diamond) usually refers to older cuts with fewer facets, while “pırlanta” means the brilliant cut.

What is a diamond?

A diamond is a mineral formed by carbon atoms arranged in a very tight structure. It is the hardest known natural material, scoring 10 on the hardness scale. Rough diamond from the earth is matte and dull; it gains its sparkle only after it is cut and polished.

What is a brilliant?

A brilliant is not a type of stone but a way of cutting one. When a diamond is cut with 57 facets calculated to return the most light, it is called a brilliant. Counting the tiny facet at the bottom tip of the stone, the number becomes 58.

In this cut, light entering the stone from the top reflects off the lower facets and comes back out through the top. That is the reason for a brilliant’s famous lively sparkle. The proportions of the cut were calculated mathematically in the early 20th century and have been refined ever since.

The differences between a diamond and a brilliant

This is also why there is a price difference between a “diamond ring” and a “brilliant ring” in Turkish shops: the brilliant cut takes more work, more of the rough stone is lost in cutting, and the finished stone is far brighter.

Are oval, pear and emerald cut stones brilliants?

Technically, “brilliant” is the name of the round cut. Shapes such as oval, pear, marquise, emerald and princess are called “fancy cuts”. In everyday language and in shop windows, however, they are all called diamonds or brilliants: “oval diamond”, “emerald cut diamond” and so on. The certificate states the stone’s shape and cutting style separately.

To see how the shapes look on the finger, you can compare eight cuts on the same hand in our ring designer.

Lab diamond or lab-grown brilliant?

Both are correct and usually mean the same thing. A stone grown in a laboratory is a diamond; when it is cut as a brilliant, it is a lab-grown brilliant. Its chemistry, hardness and light are the same as a natural diamond. More: what is a lab-grown diamond.

What to check when buying

• Read the label. The stones in a piece labelled simply “diamond” may not be brilliant cut.
• Ask about the cut. The cut decides most of a stone’s sparkle.
• Ask for a certificate. The report states the stone’s shape, cut, carat, colour and clarity.

Frequently asked questions