This specification covers refined iridium as sponge and powder in two grades, Grade 99.80 (UNS PO6100) and Grade 99.90. The metal may be produced by any refining process. They shall conform to the required chemical composition for iridium, rhodium, platinum, palladium, ruthenium, lead, silicon, tin, zinc, arsenic, bismuth, cadmium, iron, silver, gold, copper, nickel, and chromium. The sampling procedures shall consist of sponge lot and powder lot.