Knowing the Difference Between Carat and Karat

Carrot, caret, carat and karat,  are all pronounced the same, but each has a different meaning. Carat and karat, of course, have very specific meanings in jewelry. Misusing either word can be an embarrassing, if not an expensive, mistake. Spelling carats or karats as carets or carrots will make you look foolish and unprofessional.

How do you know which word is correct?

Let's look first at where the words came from, and then their current meanings. Many of us are familiar with carob, which is often used as a substitute for chocolate. Few of us, however, know that carat and karat both trace their ancestry to carob. Carob trees have grown in the Mediterranean region since antiquity. The trees produce small, edible seed pods containing carob beans. Carob beans are unusually consistent in size. This means that carob beans usually all weigh the same, no matter when or where harvested.

This characteristic of consistent weight led to carob beans becoming a unit of weight in early times. The Greeks were the first documented users of carob beans for 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.

Although they 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.

How much does a carat weigh?

Prior to 1913, a carat in the United States weighed 205.3 milligrams. In 1913 the United States accepted 200 milligrams as the international standard weight of a carat. (European countries and Japan had accepted this standard earlier.) Some jewelers use the term metric carat. A metric carat also weighs 200 milligrams. For those of us who still think in pounds and ounces, it takes about 142 carats to make an ounce.

The important thing to remember is 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. For example, a one-carat sapphire will be smaller than a one-carat diamond, because sapphires are heavier than diamonds. A karat has nothing to do with weight, but instead refers to the quantity of gold contained in a particular item. The measurement uses a base of 24 units. Pure gold is twenty-four twenty-fourths (24/24ths) gold, and is called 24-karat gold.

As gold is a soft metal, other metals are often added to make it harder. Gold with other metals added to it is referred to as a gold alloy. The most common metals used in gold alloys are silver, copper, nickel, and zinc. Gold that is 14-karat gold is fourteen twenty-fourths (14/24ths) gold and ten twenty-fourths (10/24ths) other metals. The most common gold alloys are 14-karat gold and 18-karat gold. Other alloys, such as 16-karat gold, are sometimes available.

When buying gold or objects made from gold, remember that the higher the number of karats, the higher the proportion of gold. Only 24-karat gold is 100% gold.

In addition to carats and karats, we also have carets and carrots. A caret is the symbol ^. Use a caret to show where something should be inserted in printed matter. It is derived from the Latin word for lacking. Carrot began with the Greek word for head. Carrots are important vegetables for jewelry makers-they are a rich source of vitamins that help keep our eyes healthy!

As jewelry makers, may your life be full of gemstones, which you will weigh by the carat, and gold, the purity of which you will measure by the karat.