You may have heard of “The 4 C’s of Jewelry.” This phrase is used by jewelers to describe the cut, color, clarity, and carat of a diamond. Grading systems have been put into place to technically determine the appearance and value of a stone. Carat is a term used to measure the weight of a diamond, and even though most people have heard of the term, it may be the most unknown in terms of background and what precisely it entails.

History
The term Carat was first created in 1907 at the General Conference on Weights and Measures. This was the fourth meeting of the conference, and it now takes place every 4-6 years to maintain and establish an international standard of measurements. The name carat came from the Greek word for the carob seed. Carob seeds were frequently used to weigh things like gold or diamonds because of their uniform size and weight.

What is a Carat?
A carat was determined to be 200mg or about .007 ounces in weight. There are a hundred points in a carat that are 2 mg each. If a jeweler indicates a diamond weighs 75 points, he means it weighs 75/100 of one carat, or 3/4 carat. A 25 point diamond is 1/4 carat, and a 10 point stone would be 1/10 carat. Special digital scales are now used to measure diamonds, although they have not always been precise. Generally, the higher the carat, the more expensive a diamond is. A flawless diamond is called a paragon and weighs at least 100 carats. This type of diamond is very expensive and very rare, and most stones found in jewelry stores are a lot less than 100 carats.

Some rings and other types of jewelry with multiple diamonds, such as on the band, are described by their total carat weight, or “TCW” as referred to by jewelers. This includes the combined weight of all the diamonds in a piece of jewelry, with the price of a diamond frequently described by weight per carat.

Commercial Misconceptions
It is important to remember that a carat is a measurement of weight, not the unit of size. This is particularly important to understand since many people assume that a one carat diamond represents a specific size. For example, most people would assume a one carat emerald to be the same size as a one carat diamond, which is not the case. Emeralds weigh less than diamonds, and rubies actually weigh more than diamonds. Therefore, an emerald may seem to be large, with a dimension of 9x7mm for instance, but have a lower carat weight than a diamond with smaller dimensions. If carat weight is not so much a concern as the physical size a stone appears, then look for a specific dimension rather than carat.

When shopping for a new ring or other piece of diamond jewelry, educate yourself on the carat weight that corresponds with the physical size perceived by our eyes. This will eliminate confusion with your jeweler and ensure that you will get exactly what you want.