Pyrites

n. [ L., fr. Gr. &unr_;, fr. &unr_; fire. See Pyre. ] (Min.) A name given to a number of metallic minerals, sulphides of iron, copper, cobalt, nickel, and tin, of a white or yellowish color. [ 1913 Webster ]

☞ The term was originally applied to the mineral pyrite, or iron pyrites, in allusion to its giving sparks when struck with steel. [ 1913 Webster ]

Arsenical pyrites, arsenopyrite. --
Auriferous pyrites. See under Auriferous. --
Capillary pyrites, millerite. --
Common pyrites, isometric iron disulphide; pyrite. --
Hair pyrites, millerite. --
Iron pyrites. See Pyrite. --
Magnetic pyrites, pyrrhotite. --
Tin pyrites, stannite. --
White iron pyrites, orthorhombic iron disulphide; marcasite. This includes cockscomb pyrites (a variety of marcasite, named in allusion to its form), spear pyrites, etc. --
Yellow pyrites, or
Copper pyrites, the sulphide of copper and iron; chalcopyrite. [ 1913 Webster ]