UDC 549:291,33
LBC 86.41:26.31
  K.305

RUS language
RUS
 

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

   Diagnostic cart.
   On a photo: Marcasite of plate tablet lamellar form. Down: crystals of Marcasite, paired twin (duplex) as a "cockscomb"

   Fe S2
   Crystal structure rhombic
   Hardness on the Mohs scale 6-6,5
   Specific unit weight mass 4,8-4,9
   Cleavage shows up hardly
   Fracture, break wrong
   Colors brass-yellow, gold
   Colors in powder triturate greenish-grey
   Glance (glitter, glare) metallic

   Marcasite is a sulfide of iron. Glance (glitter, glare) metallic, opaque. Colors bronze-yellow, gold. A line is greenish-gray. Fracture, break uneven. Fragile. Cleavage noperfect absolute. Appears in hydrothermal vein, lode, mines and as concretions in siltages. Crystals (rhombic Crystal structure) of plate tablet lamellar, columnar, basaltiform. Chasty twins. Usually forms joint, junction in form cock scallops (pectinate pyrites) or lanceolate (spear-shaped pyrites). A metallic pale yellow mineral consisting of iron sulphide in orthorhombic crystalline form used in jewellery. Formula: FeS2.

   Aggregates are radially-radiant, kidney-shaped reniform, there are raids. In dense aggregates outwardly undistinctive from a Pyrite. Used for the receipt preparation of sulphuric acid. Not to mix up with zircon and thorianite - by dangerous radio-active stone which by sight can be alike on golden-brown and bronze-yellow, gold unradio-active Marcasite (plate tablet lamellar sulfide of iron).

   "Marcasite" concretions, often offered as collection material, actually more frequent than all are aggregates of Pyrite. Places of distribution: Garc, Saxony (Germany, EU), Czekh (EU), CIS, Bolivia and other "Marcasite" concretion of radially-radiant structure from the deposit of Rio-tinto, Spain. More frequent than all similar concretions are pseudomorphosis of the second Pyrite on marcasite (hydrothermal recrystallization).

   Crystals more frequent all of plate tablet lamellar, but are also prismatic and pyramidal. Often there are twins in form the so-called "cockscomb", as have a dentate. Marcasite often be found as concretion with a radiant structure, and also concretionary the masses or as stalactites. In such cases with a naked eye hardness to distinguish him from a Pyrite and it is necessary to come running to the physical and chemical methods. Marcasite is opaque, cleavage shows up badly, it fragile frail brittle, hard and heavy. Colors on fresh cleavage of white, transitory in brass-yellow, gold. At oxidization on-the-spot there are colors of oxide tint blueing or darkening. Glance (glitter, glare) of Marcasite typically metallic, in powder triturate he seems darkly-grey with a greenish tint.

   Chemical composition (chemistry, compound)-maintenance (in %): Fе- 46,6; S - 53,4; in negligible quantities there are admixtures of arsenic, antimony, cobalt, thallium, Bi, copper. Rhombo-dipiramidal type of symmetry. Cleavage - noperfect absolute on (101) .Occur in nature as plate tablet lamellar, shortcolumnar, basaltiform, dipyramid, bipyramid, spear-shaped, needle-shaped crystals. Basic simple forms: (101), (110), (010), (130), (111), (100) and other Pectinate joint, junction, arising up because of frequent double is known. Much more frequent observed as concretions, kidney-shaped reniform and cluster-like formations. Pseudomorphosis is characteristic also on debrises.

   Diagnostic indication.

   At combustion Marcasite paints flame in bluish flower publishes a smell sulphur, brimstone. Under act of air and humidity he oxidizes, deputized a Pyrite and sulfates of iron.

   Origin provenance genesis.

   Larghetto widespread. Be found in low temperature hydrothermal vein, lode, mines, in the conditions of high acidity. In addition, it often is in siltages (limestones, rhumss and caustobioliths), appearing in the conditions of lack of oxygen in a restoration environment, koda with participation of bacteria from water the contained was besieged in it iron and Sulphur, Sulfur, Brimstone.

   Deposit minefield mine and use.

   Marcasite is developed in Folkstoune, Dovere and Tevistoke in Great Britain; in Excrement in France; in Karlovy Vary in Republic Czekh (EU); in Klaustale, Frayberge and Annaberg-Bukhkholce in Germany, EU. In the United States excellent standards are got from Dzhoplina and other places of mining region Three Steyt (states of Missouri, Oklahoma and Kansas, USA). Marcasite is used for the receipt preparation of sulphuric acid.