Arsenic is named from the Greek arsenikon, yellow orpiment, identified with arsenikos, male, from the belief that metals were different sexes. The element is believed to have been first extracted in 1250. It is found native in the sulfides realgar and orpiment, as arsenides and sulfarsenides of heavy metals, as the oxide, and as arsenates. Mispickel or arsenopyrite is the most common mineral, from which on heating the arsenic sublimes leaving ferrous sulfide. The element is a steel gray, very brittle, crystalline, semimetallic solid. Arsenic and its compounds are poisonous. Arsenic is used in agricultural insecticides and poisons, and as a doping agent in the semiconductor industry.