For chemical means of distinguishing pyrite from marcasite consult H.
Finely crystallized specimens of pyrite are obtained from many other localities, especially from Cornwall, Elba and Traversella, near Ivrea, in Piedmont.
Rickard, Pyrite Smelting (1905); for wet methods, see Eissler, Hydrometallurgy of Copper (London, 1902); and for electrolytic methods, see T.
Impurities.-The properties of iron and steel, like those of most of the metals, are profoundly influenced by the presence of small and sometimes extremely small quantities of certain impurities, of which the most important are phosphorus and sulphur, the former derived chiefly from apatite (phosphate of lime) and other minerals which accompany the iron ore itself, the latter from the pyrite found not only in most iron ores but in nearly all coal and coke.
In the case of coal, salt, iron ore, pyrite and other homogeneous minerals, boring may give all the information required.
Iron disulphide, FeS2, constitutes the minerals pyrite and marcasite; copper pyrites is (Cu, Fe)S2.
It occurs in nature as the mineral melanterite, either crystalline or fibrous, but usually massive; it appears to have been formed by the oxidation of pyrite or marcasite.
They are four important iron ores, magnetite, haematite, limonite and siderite, and one of less but still considerable importance, pyrite or pyrites.
Other mineral products are graphite, garnet used as an abrasive, pyrite and zinc ore.
In marls, cement-stones and argillaceous limestones); (4) sulphide of iron, as pyrite or marcasite (when finely diffused, giving the clay a dark grey-blue colour, which weathers to brown - e.g.