ISO 11426:2014 specifies a cupellation method (fire assay) for the determination of gold in gold jewellery alloys. The gold content of the alloys should preferably lie between 333 and 999 parts per thousand (?).

The procedure is applicable specifically to gold alloys incorporating silver, copper, and zinc. Some modifications are indicated where nickel and/or palladium are present in the so-called white gold alloys, as well as for alloys containing 990 or more parts per thousand (?) of gold.

ISO 11426:2014 is intended to be used as the recommended method for the determination of fineness in alloys covered by ISO 9202.