Diamond carat

Diamond Buyer's Guide

A diamond's carat is a measure of its weight, not its size. Larger carat weights are rare and valuable. However, two diamonds with the same carat weight can have very different values depending on their colour, clarity and cut.

What is a carat?

The word carat derives from ancient times, when gems were measured using the weight of a carob seed. One carat is equivalent to one fifth of a gram. It can also be divided into 100 'points.' If someone refers to a half carat diamond, this is the same as a 50 point or a 0.50 carat diamond. Similarly, a quarter carat diamond is equivalent to 25 point, or 0.25 carat.

If a piece of jewellery contains more than one diamond, for example a diamond cluster ring or a diamond three stone pendant, the stated carat weight reflects the total weight of all the stones together, rather than each individual diamond.

Is carat the same as size?

The carat weight of a diamond does not reflect its size. One diamond may look bigger than another but weigh less. A good cut and certain mounts can make a diamond appear larger than its actual carat weight, so it's worth taking your time to find the right diamond jewellery with a setting that optimises its beauty and brilliance.

Get the most from your diamond

Of all the 4 Cs, carat is often the key deciding when choosing a diamond engagement ring, pendant or earrings - especially if the jewellery you are buying features a diamond solitaire as its centrepiece. However, you should also consider that colour, clarity and cut are also important in determining a diamond's value and beauty.