The “Four Cs” of Diamond Buying
Cut. Carat. Color. Clarity

Diamonds are weighed in metric carats; one
carat is equivalent to 200 milligrams (1/5 of
a gram). One carat is divided into 100
"points," so that a diamond of 25 points is
described as a quarter of a carat, or .25
carats. Here are some examples that show
the approximate size of diamonds of varying
carat weight.