Understanding 525 & 540 Gold: What Do These Markings Mean?

The numbers 525 and 540, when stamped on jewelry, typically refer to the gold content expressed in parts per thousand. This is a system similar to using karats, but instead of a fraction out of 24, it's a fraction out of 1000.

* 525: This means the jewelry is 52.5% pure gold (525/1000). This is roughly equivalent to 12.6 karats (12.6K).

* 540: This means the jewelry is 54% pure gold (540/1000). This is roughly equivalent to 13 karats (13K).

So, jewelry marked 525 or 540 refers to gold jewelry with approximately 52.5% or 54% gold content, respectively. It's a way of indicating the fineness or purity of the gold in the piece.