What Does 999.9 Gold Mean?

Fineness is expressed in parts per thousand, so 995 means 99.5% gold and 999 means 99.9%. The additional decimal in 999.9 indicates a further order of precision, sometimes described informally as four nines.

Higher fineness does not make gold a different metal; it describes how little non-gold material remains after refining.

Investment bars are commonly produced at 999.9 or 999. Certain large wholesale bars are accepted at a minimum of 995, with the actual fine gold content recorded individually for each bar.

In wholesale trade, what is paid for is fine gold content, so a lower fineness is not automatically a worse purchase provided the content is correctly assayed and priced.

Refiners work to tolerances, and assay results can vary slightly between laboratories. Transactions therefore specify the assay basis rather than relying solely on the stamped figure.

A stamp is a claim by the producer. Verification confirms it.