ISO 11426:2021 PDF

Scope: This document specifies a cupellation method (fire assay) for the determination of gold on a material considered homogeneous. The gold content of the sample lies preferably between 100 and 999,5 parts per thousand (‰) by weight. Fineness above 999,5 ‰ can be determined using a spectroscopy method by difference (e.g. ISO 15093). The procedure is applicable to most types of gold samples. Some modifications are indicated for specific cases (presence of large amount of base metals, platinum or palladium, silver). It is not compatible with the presence above trace levels of iridium, rhodium and ruthenium (more than 0,25 ‰ for the sum of all three elements). This method is also intended to be used as the recommended method for the determination of fineness in jewellery alloys covered by ISO 9202.

ISO 11426:2021 history

2021 ISO 11426:2021 Jewellery and precious metals - Determination of gold - Cupellation method (fire assay)
2014 ISO 11426:2014 Jewellery - Determination of gold in gold jewellery alloys - Cupellation method (fire assay)
1997 ISO 11426:1997 Determination of gold in gold jewellery alloys - Cupellation method (fire assay)
1993 ISO 11426:1993 Determination of gold in gold jewellery alloys; cupellation method (fire assay)