About Diamond Weights

Diamonds are measured in Carat Weight.
One carat weighs 200 milligrams. If a
diamond is referred to as four grains, this
also means that it is a one carat diamond.

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, or one carat.
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. 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 – it 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.