How to Determine the Purity of Gold Jewelry
in Jewelry Blog

How to Determine the Purity of Gold Jewelry

Pure gold is a soft metal and not suitable for ordinary jewelry, or even extraordinary jewelry, so we know you won’t see any pure gold pieces anywhere outside of a museum. Fortunately, there are some fairly easy ways to tell the gold content of any jewelry.

Karat Content of Gold Jewelry

Almost every piece of jewelry you see has a value stamped on it. It could be stamped 14K, for example, meaning 14 out of 24 parts are pure gold and the other 10 parts are some other metal. Sometimes this value is expressed as parts per thousand, which would amount to 533 (14 divided by 24 and multiplied by 1000. Every stamp you see will be some variation of this system. Here are all the major designations for your ease in understanding them.

  • 24K – 99.99%  999
  • 22K – 91.7%    917
  • 20K – 83.3%    833
  • 18K – 75%       750
  • 14K – 58.3%    583
  • 10K – 41.7%    417

What Does “P” Mean on a Stamp?

“P” means “Plumb”, which in ordinary parlance means on the money, or exactly. In the U.S. the value of any karat designation can vary by as much as a half karat. So your 14k necklace could have as little as 13.5K in it. With the P added to the karat value, the piece must contain at least the amount stated. You know that 14k means 14k. Naturally, this added sign of purity adds a little to the price.

What Can I Do If There Is No Stamp?

Most jewelers are willing to test the items they have in the store in order to satisfy you of their relative purity. Or, if you already have a piece with no stamp, they will test it for you for a fee. If you like, you can buy a testing kit and do it yourself. You need to aware that the kit contains nitric acid, so handle with care.

Now you are better prepared when make your next jewelry purchase. You can look at a gold chain or piece and have a better idea of its value.