Marks and materials
Jewelry Hallmark Quick Reference
Search common jewelry fineness marks and see what the numbers can mean. A stamp is a clue to research, not proof of authenticity or metal content.
Showing common fineness marks and terms.
3759 carat gold
375 parts per thousand, or 37.5% gold by weight in the alloy.
41710 karat gold
417 parts per thousand, or about 41.7% gold. This number is used in some markets.
50012 karat gold
500 parts per thousand, or 50% gold by weight.
58514 karat gold
585 parts per thousand, or 58.5% gold by weight.
75018 karat gold
750 parts per thousand, or 75% gold by weight.
91622 karat gold
About 916 parts per thousand, a common 22 karat fineness mark.
999Fine gold
999 parts per thousand, commonly described as 24 karat gold.
800Silver fineness
800 parts per thousand silver in systems that use this standard.
925Sterling silver
925 parts per thousand silver, or 92.5% by weight.
958Britannia silver
About 958 parts per thousand silver in the UK standard.
950Precious-metal fineness
Used for more than one precious metal standard. Check the surrounding metal and assay marks.
GPGold plated
Often used to describe a plated finish; it is not a solid-gold fineness number.
GFGold filled
Often describes a layer of gold bonded to a base metal. It does not state a solid-gold fineness.
No common match found. Try the number alone or a metal name.
Read the marks together
A fineness number describes precious-metal content in parts per thousand. In some hallmark systems, a full hallmark also includes a maker or sponsor mark and an assay-office mark. A single stamp can be incomplete, misread or copied, so this reference cannot authenticate a piece.
For a careful walkthrough, read How to read a jewelry hallmark without treating it as proof.