Stibarsen

Stibarsen
	Globular stibarsen from the Elk Mountains (Colorado) , USA ; ( overall size : 4.7 × 3.2 × 3.2 cm)
General and classification
other names	Arsenic antimony; Allemontit II;
chemical formula	AsSb
Mineral class; (and possibly department)	Elements (including natural alloys or intermetallic compounds)
System no. to Strunz ; and to Dana	1.CA.05 ( 8th edition : I / B.01) ; 01.03.01.03
Crystallographic Data
Crystal system	trigonal
Crystal class ; symbol	ditrigonal-scalenohedral; 3 2 / m
Room group (no.)	R 3 m (No. 166)
Lattice parameters	a = 4.02 Å ; c = 10.80 Å
Formula units	Z = 3
Physical Properties
Mohs hardness	3 to 4
Density (g / cm 3 )	measured: 5.8 to 6.2; calculated: 6.44
Cleavage	perfectly
colour	tin white or reddish gray, tapering gray to black
Line color	Gray
transparency	opaque
shine	Metallic gloss to matt

Stibarsen is a rarely occurring mineral from the mineral class of the " elements (including natural alloys or intermetallic compounds )". It crystallizes in the trigonal crystal system with the composition AsSb, is thus chemically an intermetallic phase consisting of arsenic and antimony (not to be confused with the Allemontit designated batch of stibarsen, arsenic and / or antimony).

Stibarsen is opaque in every form and only develops indistinct crystals . It is mostly found in the form of grape, kidney-shaped, lamellar or fine-grain mineral aggregates , often also grown together with arsenic or antimony and forming demixing structures. Fresh samples are pewter-white or reddish-gray in color and have a metallic sheen , but after a while they become gray to black and become matt.

Etymology and history

Stibarsen was first discovered near Varuträsk in the Swedish municipality of Skellefteå and was described in 1941 by PE Wretblad, who named the mineral after its composition antimony (Latin stibium ) and arsenic.

classification

In the meanwhile outdated, but still in use 8th edition of the mineral classification according to Strunz , the stibarsen belonged to the department of "semimetals and non-metals", where together with antimony , arsenic , arsenolamprit , bismuth , paradocrasite and pararsenolamprit it forms the "arsenic group" with the System no. I / B.01 formed.

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also classifies the Stibarsen in the division of "semi-metals (metalloids) and non-metals". This is, however, further subdivided according to element groups, so that the mineral can be found according to its composition in the subdivision of the "arsenic group elements", where the "arsenic group" with the system no. Is only found together with antimony, arsenic and bismuth . 1.CA.05 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the stibarsen to the "elements" department and here, too, as a member of the "arsenic group" with system no. 01.03.01 to be found in the subsection of " Elements: Semi-Metals and Non-Metals ".

Modifications and varieties

Named after its type locality Allemond (English Allemont than) in France Allemontit called eutectoid mixture of stibarsen, arsenic and / or antimony, in contrast to pure stibarsen typical demixing.

Education and Locations

Shiny silver, coarse Stibarsen handpiece from the " Moctezuma Mine", Sonora, Mexico (size: 5.8 × 3.0 × 1.6 cm)

Stibarsen found generally in hydrothermal - veins , but also in pegmatites . In addition to arsenic and antimony, arsenolite , calcite , cervantite , kermesite , quartz , siderite , sphalerite , stibnite and stibiconite are accompanying minerals .

As a rare mineral formation, Stibarsen could so far (status: 2013) only be proven at a few sites, with around 40 sites being known. In addition to its type locality Varuträsk, the mineral was found in Sweden in the "Åkerberg" mine near Skellefteå (Västerbotten) as well as in the "Jakobsberg" and "Kittel" mines near Nordmark and Långban in Filipstad (Värmland).

Příbram and Třebsko in the Czech Republic, where up to 10 centimeters large, grape-like aggregates were found, are known for their extraordinary stibarsen finds . Bunchy specimens, up to 8 centimeters in size, were also found in the Atlin mining area in the Canadian province of British Columbia.

At German localities far are Reinerzau in the Black Forest, a gabbro -Steinbruch in Bad Harzburg and the mines "Claus-Friedrich" and "Samson" in Sankt Andreasberg in Lower Saxony resin and the mine "Father Abraham" in Lauta (Marienberg) in Erzgebirgskreis known.

In Austria, Stibarsen has only appeared on the Hüttenberger Erzberg in Carinthia and on the Zinkwand in the Schladminger Tauern in Styria.

Other locations include Broken Hill in Australia, Porco (Potosí) in Bolivia, the "Les Chalanches Mine" near Allemond (English Allemont ) in the French department of Isère , several locations in the Greek region of Attica , the Stabiello Alp near Sondalo in Italy, the “Yagumo Mine” on Hokkaidō and the “Bajo Mine” on Kyūshū in Japan, Sonora in Mexico, Szklarnia (German Glass Village ) in Poland, Kawalerowo in Russia, Zlatá Baňa in Slovakia, Adrasman in Tajikistan and the mineral discovery site “American Eagle / Luona ”in the Elk Mountains (Colorado) and the“ Ophir Mine ”in Comstock Lode (Nevada) in the USA.

Crystal structure

Four unit cells of the stibarsen structure

Stibarsen crystallizes trigonal in the space group R 3 m (space group no. 166) with the lattice parameters a = 4.02 Å and c = 10.80 Å as well as 3 formula units per unit cell .

literature

W. Trsebiatkowski, E. Bryjak: X-ray analysis of the system arsenic-antimony. In: Journal of Inorganic and General Chemistry. Volume 238, 1938, pp. 255-267 ( rruff.info PDF; 749.1 kB).
PE Wretblad: Minerals of the Varuträsk Pegmatite. XX. The Allemontite and the As-Sb system. in: Geologiska Föreningens i Stockholm Förhandlingar. Volume 63, 1941, pp. 19-48 ( rruff.info PDF; 1.29 MB).
Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 402 (first edition: 1891).

Web links

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

Individual evidence

↑ ^a ^b Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1987, ISBN 3-342-00288-3 , p. 285 .
↑ ^a ^b ^c ^d Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 50 .
↑ Stibarsen. 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 57.4 kB).
↑ Mindat - Number of localities for stibarsen.
↑ Petr Korbel, Milan Novák: Mineral Encyclopedia (= Dörfler Natur ). Nebel Verlag GmbH, Eggolsheim 2002, ISBN 3-89555-076-0 , p. 14 .
↑ Mindat - Stibarsen.

[Rösler-1] Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1987, ISBN 3-342-00288-3 , p. 285 .

[StrunzNickel-2] Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 50 .

[Datenblatt-3] Stibarsen. 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 57.4 kB).

[MindatAnzahl-4] Mindat - Number of localities for stibarsen.

[Dörfler-5] Petr Korbel, Milan Novák: Mineral Encyclopedia (= Dörfler Natur ). Nebel Verlag GmbH, Eggolsheim 2002, ISBN 3-89555-076-0 , p. 14 .

[Mindat-6] Mindat - Stibarsen.