Weight
Precious metals are quoted in several standard units.
Common formats include:
Product specifications should distinguish clearly between gross weight and actual fine-metal content where relevant.
Purity and fineness
What do 999, 999.9 and 916.7 mean?
Fineness expresses how much of a product consists of the stated precious metal.
999.9
Generally indicates 999.9 parts of precious metal per 1,000.
999
Indicates 999 parts per 1,000.
916.7
A product marked 916.7 contains a lower proportion of the stated precious metal and may use other metals within the alloy.
Purity matters because the value of physical bullion depends on the quantity of actual precious metal present.