Natural Occurrences

Cadmium never occurs in nature in its elemental form. It is always found in a compound with another element. The most common natural compounds of Cadmium are Cadmium Sulfide, Cadmium Carbonate, and Carbon Oxide. Carbon Sulfide, also known as the mineral Greenockite, is the most well known source of Cadmium. Cadmium is also found in the Earth's Crust in amounts of about 0.1 to .2 ppm, a very smallamount. Most of the Cadmium that is obtained is through a process known as Zinc refinement, which uses their differing melting points.