09 January 2020

How to pick your perfect diamond: The 4Cs

Are you on the hunt for a beautiful diamond ring for yourself or a loved one? At a glance diamonds may all look the same, but each one is distinctly different. You'll find the price and size of a diamond can vary greatly, depending on four key characteristics. These are known as the 4Cs, or colour, cut, clarity and carat.

Here's a short guide to help you better understand what makes a diamond especially rare and precious, or particularly colourful and full of character! 



While we talk about colour in diamonds, it’s really the absence of colour that defines how precious and high quality a diamond is. When we’re assessing a diamond, we colour grade it on a finely-tuned scale of D through to Z. The most precious diamonds are completely colourless and receive the highest accolade of D. At the lowest end of the range is Z for ‘saturated’ diamonds which are dark yellow in colour and least expensive.




The way in which a diamond is cut greatly determines its beauty. Our diamond cutters are masters of their craft, precisely faceting each diamond to maximise its brilliance, scintillation and fire. There are many different ways to cut a diamond. Emerald, cushion and marquise cuts are classic choices, and the round brilliant cut is by far the most popular. It’s the quality of that cut that confirms your diamond’s true value.




Just how pure is your diamond? Almost all diamonds will have imperfections known as ‘inclusions’ or ‘blemishes’. The perfectly flawless diamond is a rare find! This is because diamonds are formed deep in the earth through a natural process of carbon exposed to tremendous heat and pressure. When we grade a diamond we look at its internal and external clarity. The most flawless of diamonds receive the ultimate grading of LC (loupe clear and flawless).




A diamond’s weight is measured in carats: 0.20 grams = 1 carat. The larger the diamond the more rare and desirable it is, making it more valuable. However weight does not necessarily determine value. Two diamonds of equal weight can vary in price depending on the quality of their colour, cut and clarity. And a large diamond of excellent quality is a rare and precious find.

If you like this article, you may like to read about how to select an ethical diamond, too.

The 4Cs is brought to you by the Pieces of Eight Gem School


Images from top: Anna Sheffield, Melanie Katsalidis, Katherine Bowman, Ruth Tomlinson