Karat, Carat, and Carrot are all pronounced the same, but each has a very different meaning. Karat and carat are specific jewelry terms, and carrot, of course, is an orange root vegetable.

I often see the words carat and karat missused, so I did some research on the two terms. Looking into the etymology, or history of the two words, helps to shed some light on these similar-sounding terms.

Both carat and karat trace their ancestry to the word ‘carob’, which is a common substitute for chocolate. Carob trees grow prolifically in the Mediterranean region and they produce small, edible seed pods that contain carob beans. These beans are uncannily consistent in size, meaning that carob beans usually weigh the same amount, no matter where or when they are harvested.

As a result of this characteristic of consistent weight, carob beans became a unit of weight in early times. The Greeks were the first documented users of carob beans for weight. By 1500, Latin alchemists, who were still using carob beans as a basic unit to measure weight, measured things by the carratus. Carat and karat are the modern derivitives of carratus.

Although their origin and pronounciation are the same, carat and karat have very different meanings. Carat is a unit of weight for gemstones; and karat is a unit for measuring the purity of gold.

It is important to remember that a carat is a unit of weight and not a unit of size. One carat of a dense stone will be smaller in appearance than one carat of a light-weight stone. For example, one carat of a blue sapphire will be smaller than one carat of a diamond, since sapphire is more dense than diamond.

On the otherhand, a karat has nothing to do with weight, but instead refers to the quantity of pure gold contained in an object, out of a 24-unit whole. Hence, 24 k gold, is 100% gold, and is 24/24ths gold.

Because gold is a soft metal, other metals are often added to it, or alloyed with it, to make it harder. The most common metals used in gold alloys are silver, copper, zinc, and nickel. Gold that is 14 k is 14/24ths gold and 10 k is 10/24ths gold (and 14/24ths other metals).

So when purchasing gold jewelry, remember that the higher the number of karats, the higher the quantity of pure gold. And the larger the number of carats, the more a gemstone will weigh.