Cadmium is Natural. Cadmium (elemental symbol Cd and CAS registry number 7440-43-9) is a member, along with zinc and mercury, of Group 12 (CAS IIB) of the Periodic Table of the Elements. It is generally characterized as a soft, ductile, silver-white or bluish-white metal, and is listed as 64th in relative abundance amongst the naturally occurring elements. Cadmium is found principally in association with zinc sulfide based ores and, to a lesser degree, as an impurity in lead and copper ores. It is also found in sedimentary rocks at higher levels than in igneous or metamorphic rocks, with the exception of course of the nonferrous metallic ores of zinc, lead and copper.