Magnetic pyrite

Many of these sulphides occur naturally, for example iron(ll) sulphide, FeS (magnetic pyrites), and antimony(III) sulphide, Sb S, (stibnite). They can usually be prepared by the direct combination of the elements, effected by heating, but this rarely produces a pure stoichiometric compound and the product often contains a slight excess of the metal, or of sulphur. 

Charles Hatchett analyzed magnetic pyrite and stated that the discovery of iron in pyrite is comparatively recent. According to Henckel, said he, this was first noticed by our countryman Martin Lister, a member of this learned Society [the Royal Society]. .. (182). 

Hatchett, Charles, An analysis of the magnetical pyrites with remarks on... 

PYRRHOTITE. The mineral pyrrhotite, sometimes called magnetic pyrites, is a sulfide of iron with varying amounts of sulfur. Analyses indicate formulae Fe S, Pyrrhotite exists in two modifications it is monoclmic below, and hexagonal above (280°F). It is a brittle... 

The pyrrhotite or magnetic pyrites is essentially iron sulphide, Fe,Sg or 4FeS.Fe3S4 chalcopyrite or copper pyrites, Cu2S.Fe.jS3, contains some 35 per cent of copper, whilst the pentlandite contains the nickel as sulphide associated with iron sulphide, thus, NiS.2FeS, and contains approximately 22 per cent, of nickel. 

Magnesioferrite. Magnetic pyrites MgO Fe203 4FeS.Fe3S4 4 57-4 65 4-4-4-7 6-6 5 3 5-4 5 Cubic. Two varieties, hexagonal and rhombic. 

Iron and Sulphur—Subsulphides of Iron—Ferrous Sulphide—Ferric Sulphide-Double Sulphides—Iron Pyrites—Marcasite—Magnetic Pyrites—Ferrous Sulphite—Ferri-sulphites—Ferrous Sulphate—Double Sulphates—Fern-sulphates—Alums—Anndo-sulphonates, Thiosulphate, Disulphate, and Thionates of Iron. 

Ferric Disulphide— FeS,—119.0—occurs iu the white and yeliow Martial pyrites used in the manufacture of H SO. When heated in air it is decomposed into SO, and magnetic pyrites SPeS, + 20, = Fe,S, -4 2SO,. 

Ferric Disulfid—FeSa—119.9 — occurs in the white yellov> Martial pyrites, used in the manufacture of HaSO. When heated in air, it is decomposed into SOa and magnetic pyrites 3FeSa -k 30a —FeaS -H3SOa. 

Syn. Iron Pyrites.—This a very abundant mineral, of a yellow colour and metallic lustre, crystallising in cubes or octahedrons. When heated in close vessels, it loses nearly half its sulphur, which may be collected, magnetic pyrites being left. Iron pyrites is often contaminated with arsenic, which accompanies the sulphur, and is found in the sulphuric acid made from it. 

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