Cadmium

Cadmium is a soft, silvery-white metal chemically similar to zinc. It can be shaped easily and resists corrosion, making it useful as a protective coating on other metals. In nature, cadmium occurs mainly in small amounts in zinc ores, including the mineral sphalerite. Most commercial cadmium is recovered as a by-product when these ores are processed to make zinc. Cadmium has been widely used in rechargeable nickel–cadmium batteries, although other battery types have replaced many of them. Its compound cadmium telluride is used in some solar cells to help turn sunlight into electricity. Cadmium is toxic, so health and environmental concerns have led to restrictions on many of its uses.