Marcasite and pyrrhotite, other iron sulphide minerals, are frequently found with pyrite and are used for the same purposes.
pyrrhotite, or magnetic pyrites, is the source of about all the nickel of commerce.
The copper deposits are mainly in well-marked fracture planes in serpentine; the ore is pyrrhotite, with or without chalcopyrite.
One of the best-known localities is Bodenmais, in Bavaria, where it occurs with pyrrhotite in a granite matrix.
The pyritic ores of iron, including marcasite, pyrrhotite and mispickel, are often taken for gold by the inexperienced.