Platinum Iridium Jewelry. The first evidence of platinum use was in ancient egypt between 1200 and 700bc. Jewelers create platinum alloys because they are harder and usually more lightweight than platinum alone.
Spectral interferences of au, cr, cu, fe, ni and pt to ir at specific wavelengths have been investigated. By this measure (volume), 10% iridium platinum is only a bit less pure than 5% ruthenium platinum. The spectral coincidence profiles were recorded and interfering lines were identified.