Stone, minerals and semiprecious of the world stone
Sulphide: Pyrrotine -->rus

   Diagnostic cart.
   Two forms of crystals of Pyrrotine: plate tablet lamellar forms (on the right); lamellar tabular aggregates (down)

   Fe S
   Crystal structure hexagonal
   Hardness on the Mohs scale 3,5-4,5
   Specific unit weight mass 4,5-4,7
   Cleavage perfect absolute
   Fracture, break wrong
   Colors reddish-yellow, gold
   Colors in powder triturate grey-black
   Glance (glitter, glare) metallic

   Pyrrotine (magnetic pyrites), is a sulfide of iron. Glance (glitter, glare) metallic with dim oxide tint; opaque. Colors bronze-yellow, gold. A line is greyish-black. Fracture, break padman, uneven. Fragile. Cleavage perfect absolute, magnetic.

   Be found in magmatic deposits, related to the rocks of the first team, rarer in pegmatites, skarn and in hydrothermal deposits. Crystals (hexagonal Crystal structure) are rare; they are lamellar tabular, plate tablet lamellar or columnar, basaltiform, often form a group in wall outlets: dense aggregates are more ordinary: coarse-grained, sterny, short-grained or downlow, rarer fissile. Places of distribution: Germany, Finland, Norway, Yugoslavia, Republic of South Africa, Canada, CIS.

   Pyrrotine be found as plate tablet lamellar crystals, but most widespread are grainy massive aggregates. His characteristic color on fresh surfaces - reddish-yellow, gold or bronze-yellow, gold, on air russets. Glance (glitter, glare) metallic. Opaque. Enough often covered iridescent tape.

   Chemical composition (chemistry, compound)-maintenance (in %): S - 36,4-40; Fe - 60-63,6; the admixtures of copper, nickel, cobalt are sometimes marked. DiHexagonal-dipyramidal type of symmetry. Cleavage - noperfect absolute to on (1010). Be found usually as continuous the masses or sprinkled grains of wrong form. Crystals are observed rarely, lamellar tabular is typical, columnar, basaltiform, barrel-shaped dolioform type with the verges of pinacoid (0001), prisms (1010), dipyramids (1011) and (2021), twins and branch boxes are known also to on (1011).

   Diagnostic indication.

   For Pyrrotine magnetic properties are characteristic; it melt fuse easily, forming black mass, also strongly magnetic.

   Origin provenance genesis.

   Mineral, typical for a magmatic segregation. Appears above all things at hardening of intrusion, irruption basic and ultrabasic rocks (enriched iron and magnesium). In this type of deposits of Pyrrotine always associated with the minerals of nickel and cobalt, which have an economic value. Can also have a hydatogenesis, but such Pyrrotines never are rock stone nickel-contain.

   Deposit minefield mine and use.

   The enormous deposits of Pyrrotine are exposed in Sadberi, a province Manitoba (Canada). Found out other considerable deposits in Mexico, Bolivia, Brazil, Norway and Sweden. Pyrrotine, if it is deprived admixtures, presents no industrial value. Vice versa, if it is enriched a nickel, cobalt or platinum, his economic value as ores on these elements extraordinarily great. Pyrrotine - one of very much not many magnetic minerals. Plays an important role in the production of green vitriol and crocus.

Pyrrotine. Nikolaevskiy mine, Dalnegorsk, Seashore, Russia (CIS). A photo: © A.A. Evseev.