Diamond
Weight
How Diamond Weight is
Measured
Even if you're not all that knowledgable about diamonds, you probably well know that diamonds weight is measured
in carats. But there are two ways that diamond weight is measured: in carat and grains of rice. Here's some info
about the origins of these measures and what they mean.
Diamond Weight in Carats
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. This refers to diamond weight measured in rice - see the
chapter below.
Did you know that the word Carat comes from the word carob? A carob is a bean (legume) that grows on a tree in
the Mediterranean region. In times past, if a diamond weighed the same as a carob bean, it was one carob, or one
carat.
Weight of a Diamond in Rice
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.
Carat Total Weight
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.
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