Hypercinnabarite

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Hypercinnabarite
Hypercinnabar.jpg
Black hypercinnabarite crystals in matrix from Clear Creek, San Benito County , California
General and classification
other names

IMA 1977-D

chemical formula HgS or γ-HgS
Mineral class
(and possibly department)
Sulfides and sulfosalts
System no. to Strunz
and to Dana
2.CB.45 ( 8th edition : II / C.18)
08/02/08/01
Crystallographic Data
Crystal system hexagonal
Crystal class ; symbol not defined
Lattice parameters a  = 7.01  Å ; c  = 14.13 Å
Formula units Z  = 12
Physical Properties
Mohs hardness 3
Density (g / cm 3 ) measured: 7.43; calculated: 7.54
Cleavage no
Break ; Tenacity slightly scalloped to uneven
colour black red
Line color dark black purple
transparency translucent
shine Diamond luster
Crystal optics
Refractive indices n ω  = 2.610
n ε  = 2.850
Birefringence δ = 0.240
Optical character uniaxial positive

Hypercinnabarite is a very rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the hexagonal crystal system with the composition HgS and develops only microscopic crystals of black color with a tinge of violet. His stroke color is also dark black purple

Etymology and history

Hypercinnabarite was first found in 1978 in the "Mount Diablo Mine" near Clayton (Contra Costa County, California) in the USA and described by RW Potter and HL Barnes, who named the mineral in relation to its close relationship with cinnabarite and metacinnabarite .

classification

In the old (8th edition) and the new systematics of minerals according to Strunz (9th edition) , hypercinnabarite belongs to the division of “sulfides and sulfosalts with a molar ratio of metal: sulfur, selenium, tellurium = 1: 1”. However, the 9th edition of Strunz's mineral classification now subdivides more precisely according to the type of cations involved and the mineral is accordingly in the sub-section "with zinc (Zn), iron (Fe), copper (Cu), silver (Ag) etc. ”, where it forms its own group together with cadmoselite , greenockite , rambergite and wurtzite .

The Dana system of minerals used in the English-speaking world assigns hypercinnabarite to the subdivision of "Sulphides including selenides and tellurides with the general composition A m B n X p and the molar ratio (m + n): p = 1: 1". There he is the only member of the unnamed group 02.08.08 .

Crystal structure

Hypercinnabarite crystallizes in the hexagonal crystal system in a space group that has not yet been determined with the lattice parameters a  = 7.01  Å and c  = 14.13 Å as well as 12 formula units per unit cell .

Modifications and varieties

From a chemical point of view, hypercinnabarite is the high temperature modification of three modifications of mercury sulfide (HgS). The other two are the trigonal crystallizing cinnabar and the cubic crystallizing metacinnabar.

Education and Locations

Since hypercinnabarite is closely related to metacinnabarite, it forms like this in mercury deposits, but at higher temperatures, that is, in deeper layers of the earth.

So far, in addition to its type locality "Mount Diablo Mine" (California), three other sites are known for the mineral (status: 2018): The "White Caps Mine" near Manhattan (Nevada) in Nye County (USA), the antimony  (Sb) Mercury deposit of Chauwai (Russian: Чаувай) in the Alai Mountains of Kyrgyzstan and the "Monarch Cinnabar mine" in the South African province of Limpopo .

See also

Web links

Commons : Hypercinnabarit  - collection of images, videos and audio files

Individual evidence

  1. ^ A b c Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p.  82 .
  2. a b Hypercinnabar . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; 48  kB ; accessed on June 4, 2018]).
  3. a b c Mindat - Hypercinnabar (English)
  4. List of locations for hypercinnabarite in the Mineralienatlas and Mindat