Velikit

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Velikit
General and classification
chemical formula (Cu, Hg) 11 Sn 4 S 16
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.CB.15a ( 8th edition : II / C.06)
02.09.02.08
Crystallographic Data
Crystal system tetragonal
Crystal class ; symbol 4th
Space group I 4
Lattice parameters a  = 5.786  Å ; c  = 10.905 Å
Formula units Z  = 2
Physical Properties
Mohs hardness 4th
Density (g / cm 3 ) 4.45 to 5.59
Cleavage Please complete!
colour dark gray
Line color Please complete!
transparency opaque
shine metallic

Velikit is a very rarely occurring mineral from the mineral class of sulfides and sulfosalts . It crystallizes in the tetragonal crystal system with the chemical composition (Cu, Hg) 11 Sn 4 S 16 and forms small grains and tetragonal, up to one millimeter large crystals of dark gray color.

Etymology and history

The mineral was first described in 1977 by LN Kaplunnik, EA Pobedimskaya, and NW Below, but they only published a crystal structure and not a full description. The mineral has also not been recognized by the CNMMN . This only happened in 1997 after a more detailed description by VS Gruzdev, VY Volgin, EM Spiridonov, TL Evstigneeva, YK Kabalov, VI Sorokin, EG Osadchyi, TN Chvileva and NM Chernizova using a mineral sample from the antimony - mercury deposit of Khaidarkan (Chaidarkan) in the Fergana Valley in the Kyrgyz Alai Mountains . It is named after the Soviet mineralogist AS Velikiy.

classification

In the Strunz system , Velikit is classified under the sulfides and sulfosalts. It is counted among the sulphides with a ratio of metal to sulfur, selenium or tellurium of 1: 1. In the eighth edition it formed a group with barquillite , briartite , černýite , famatinite , ferrokësterite , hocartite , kësterite , kuramite , luzonite , permingeatite , petrukite , sakuraiite , rhodostannite , stannite , toyohaite and pirquitasite . In the ninth edition , the sulfides are also subdivided according to cations, where velikite mt černýite, ferrokësterite, hocartite, idaite, kësterite, kuramite, mohite, stannite, stannoidite and pirquitasite form a subgroup of metal sulfides with a ratio of metal to sulfur, selenium or tellurium of 1: 1 and zinc , iron , copper or silver .

In the systematics of minerals according to Dana it forms with stannite, černýite, briartite, kuramite, hocartite, sakuraiite, pirquitasite, kësterite, ferrokësterite and barquillite the stannite subgroup of sulphides - including selenides and tellurides - with the composition Am Bn Xp, with ( m + n): p = 1: 1.

Education and Locations

Velikite is associated with quartz , fluorite , stibnite , mercury-containing sphalerite , metacinnabarite , pyrite , actashite and livingstonite .

In addition to the type locality in Kyrgyzstan, only Chauvai, also in Kyrgyzstan, and the Campbell mine in Bisbee in the US state of Arizona are known.

Crystal structure

Velikit crystallizes in the tetragonal crystal system in the space group I 4 with the lattice parameters a = 5.786  Å and c = 10.905 Å, as well as two formula units per unit cell .

See also

Individual evidence

  1. ↑ a b c d e f g V.S. Gruzdev, VY Volgin, EM Spiridonov, TL Evstigneeva, YK Kabalov, VI Sorokin, EG Osadchyi, TN Chvileva, NM Chernizova: Velikite Cu 2 HgSnS 4 (mercurian member of the stannite group) —a new mineral . In: Zapiski Vseross. Mineral. Obshch. 1997, 126, pp. 71-75 ( abstract in American Mineralogist, p. 1118 ; PDF; 71 kB).
  2. ↑ LN Kaplunnik, EA Pobedimskaya, N. W. Below: The crystal structure of velikite, Cu 3.75 Hg 1.75 Sn 2 S 8 . In: Kristallografya . 1977, 22, pp. 175-177 ( abstract in American Mineralogist, p. 1260 ; PDF; 480 kB).
  3. ↑ VS Gruzdev, V.Yu. Volgin, EM Spiridonov, LN Kaplunnik, Ye.A. Pobedimskaya, TN Chvileva, NM Chernitsova: Velikite Cu 2 HgSnS 4 -The mercury member of the stannite group. In: Doklady Akad. Nauk. SSSR. 1988, 300, pp. 432-435 ( abstract in American Mineralogist, p. 933 ; PDF; 841 kB).
  4. ^ List of minerals according to Dana at webmineral.com
  5. ↑ Velikit at mindat.org (Eng.)

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