How Do We Determine the Number of Karats in Gold Earrings?

Buying gold earrings often involves a substantial investment, so it is crucial to know how many gold karats (also spelled "carats") the jewelry contains. The karat is the international standard for the ratio of gold to other metals in a piece of jewelry. Thus, when the karat increases, so does the purity (and the cost) of the earring.

According to dyjewels.com, all jewelry made in North America is stamped with the karat number. However, jewelry made in Italy is stamped with a "fineness number" instead. If you are buying Italian-made jewelry, you will need to convert this fineness number into karats. This can be done through simple math.

Instructions

Converting Fineness Numbers into Karats

1

Determine the three-digit fineness number. Italian-made gold jewelry is legally required to be stamped with a fineness number. The most common fineness numbers, in increasing order of purity, are: 417, 583, 750 and 917.

2

Divide the fineness number by 1,000, using your calculator or figure it out with pen and paper. For example, an earring with a fineness number of 417 divided by 1,000 is .4170.

3

Multiply the remainder by 24. For example, .4170 multiplied by 24 is 10.008. Round this number up or down (10.008 becomes an even 10).

4

This final number is the number of karats in the earrings. Gold karats are measured on a scale of 1-24. Twenty-four karat gold is rare, because, according to Gillet's Jewellers, it is often too malleable to produce a durable piece of jewelry.