Diamond Weight

How diamond weight is measured

Although there are two ways to measure diamond weight, more widely used method is that of diamond weight being measured in carats. One diamond carat weighs 200 miligrams.

Diamond carat weight origin

The word Carat comes from the word carob. A carob is a bean that grows on a tree in the Mediterranean. In times past, if a diamond weighed the same as a carob bean, it was one carob. Hence the name of of carat for diamond weight. One carat is actually the weight of one bean of carob, which is now determined more precisely to be 200 miligrams.

Diamond grains weight origin

However, in the Far East, where Carob trees do not grow, rice was used to measure the weight of a diamond. If a diamond weighed as much as four grains of rice, it was four grains – or one carat as we know it to be now.

The majority of diamond purchases are for diamonds that are 1/3 of a carat, which doesn't easy translate into grains. So using carats to measure diamond weight provde to be more practical.

Carat total weight caution

Beware when shopping for diamonds that are already set or mounted. If more than one diamond is used in the piece, the tag on the jewelry will give the CTW or Carat Total Weight. 

But this does not tell you the carat weight of each stone in the piece. You need to ask the jeweler for the total carat weight of the largest diamond in the piece to truly understand what you are buying.