It's Elemental

Cadmium was discovered by Friedrich Strohmeyer, a German chemist, in 1817 while studying samples of calamine (ZnCO₃). When heated, Strohmeyer noticed that some samples of calamine glowed with a yellow color while other samples did not. After further examination, he determined that the calamine that changed color when heated contained trace amounts of a new element. There is only one mineral that contains significant amounts of cadmium, greenockite (CdS), but it is not common enough to mine profitably. Fortunately, small amounts of cadmium are found in zinc ores and most of the cadmium produced today is obtained as a byproduct of mining and refining zinc.

Cadmium is a poisonous metal and its use is somewhat limited for this reason. Like zinc, cadmium can be electroplated to other materials to protect them from corrosion. Cadmium easily absorbs neutrons and is used to make control rods for nuclear reactors. Cadmium is also used in rechargeable nickel-cadmium batteries.

Cadmium is alloyed with silver to form solder, a metal with a relatively low melting point used to join electrical components, pipes and other metallic items. Cadmium based solders must be handled with care to prevent cadmium poisoning. Cadmium alloys are also used to make low friction bearings that are highly resistant to fatigue.

Hydrated cadmium sulfate (3CdSO₄·5H₂O), one of cadmium's compounds, is used in a device called a Weston cell, a type of battery that produces a precise voltage used to calibrate medical and laboratory equipment. Cadmium sulfide (CdS), another cadmium compound, is a yellow powder that is used as a pigment. Other cadmium compounds are used in the phosphors of black and white television sets and in the blue and green phosphors in color television sets.