Gold Jewelry - What Do the Purity Markings Mean?

Gold jewelry comes in several different grades of purity, from 10 karat to 24. Since you can't tell how pure gold is just by looking, you have to rely on the markings that are stamped on the piece of jewelry. But, exactly what do they mean, and which markings should you be looking for?

First of all, the reason any gold jewelry would be less than 100 percent pure is that gold is soft, so other metals are mixed in to strengthen the jewelry. In the United States, the purity of gold is measured in karats, which work just like percentage points- except that there are 24 rather than 100. For example, 24 karat is the same as 100% pure, and 12 karat is the same as 50% pure.

In Europe, purity is usually measured in parts per thousand. These also work like percentage points, except that there are 1000 rather than 100. For example, 750 parts per thousand (PPT) equals 75% pure.

The karatage (number of karats) or PPT of the gold jewelry is usually stamped somewhere in an unobtrusive place, like the inside of a ring. If you look there, you might see a tiny "14K", "750", or something similar. Here are some common markings and the gold content they refer to:

24K or 999 gold is 100% pure.

22K or 917 gold is 92% pure.

18K or 750 gold is 75% pure.

14K or 585 gold is 58% pure.

10K or 417 gold is 42% pure.

So, which markings, or karatage, should you look for when buying gold jewelry? It depends on a few factors:

Your budget- higher percentages of gold will make the jewelry more valuable, and lower percentages make it more affordable.
Desired color- if you are looking for white gold jewelry, this is typically 14 karat gold that has been mixed with white-colored metals like silver or zinc.
Metal allergies- if you have a skin allergy to nickel or another metal that might be mixed with the jewelry, you should consider 22 or 24 karat gold.
Strength- since 24 karat gold is fairly soft, any jewelry that requires some strength should be mixed with stronger metals. For example, necklaces are often made from 10 or 14 karat gold.