Looks like similar words sounds like can be pronounced the same, but each has a different meaning. Carat and karat, have very specific meanings in jewelry, if we misusing either word can be an embarrassing, and possible an expensive mistake. Spelling carats or karats wrongly may make you look unprofessional.
Although both words have a common origin and are pronounced the same, carat and karat now have different meanings. A carat is a unit of weight in gemstones. A karat is a unit for measuring the purity of gold. Carat is abbreviated as c. or ct., while karat is k. or kt.
We can say that back in the times fo the greeks they used of carob beans to weight . By 1500, Latin alchemists, still using carob beans as a basic unit of weight, measured things by the carratus. Carat and karat are the modern derivatives of carratus.
Carat & Karat
Prior to 1913, a carat in the United States weighed 205.3 milligrams. Was accepted in 1913 the United States 200 milligrams as the international standard weight of a carat. Now is worldwide accepted at the jewelry industry (as a reference 142 carats is approximately an ounce). In some countries we have to talk about points, in this case a carat is divided into 100 points, therefore, a 25 point diamond is also called a 1/4 carat.
For general understanding is important to remember that a carat is a unit of weight, not a unit of size. One carat of a dense heavy stone will be smaller than one carat of a lighter stone.
In the other side a karat is not related with weight, but instead refers to the quantity of gold contained in a particular item. In this case measurement uses a base of 24 units. Pure gold is 24 of 24 gold and is called 24-karat gold.