Starbergite

Starbergite
	Sternbergite and pyargyrite from Jáchymov , Czech Republic
General and classification
other names	Argyropyrite; Argyropyrrhotite; Frieseit;
chemical formula	AgFe 2 S 3
Mineral class; (and possibly department)	Sulfides and sulfosalts
System no. to Strunz ; and to Dana	2.CB.65 ( 8th edition : II / C.14) ; 09/02/12/01
Crystallographic Data
Crystal system	orthorhombic
Crystal class ; symbol	orthorhombic-dipyramidal; 2 / m 2 / m 2 / m
Space group	Ccme (No. 64, position 2)
Lattice parameters	a = 6.61 Å ; b = 11.64 Å; c = 12.69 Å
Formula units	Z = 8
Twinning	lamellar along {130}
Physical Properties
Mohs hardness	1 to 1.5 (VHN 50 = 31–44)
Density (g / cm 3 )	measured: 4.101 to 4.215; calculated: 4.275
Cleavage	completely after {001}
colour	light brown
Line color	black
transparency	opaque
shine	Metallic luster

Sternbergite is a rarely occurring mineral from the mineral class of " sulfides and sulfosalts " with the chemical composition AgFe ₂ S ₃ and is therefore chemically a silver - iron sulfide.

Sternbergite crystallizes in the orthorhombic crystal system and forms pseudo-hexagonal, tabular crystals of up to 0.6 cm in size from tombac to light brown in color, which are often arranged in rosette-shaped mineral aggregates .

Etymology and history

Kaspar Graf Sternberg

The mineral was first described in 1827 by Wilhelm Ritter von Haidinger , who a year earlier had already received two samples of a mineral that could not be assigned to any known species. One came from the mineralogical collection of the National Museum (of Prague, formerly the Patriotic Museum of the Bohemian Empire ) administered by Franz Xaver Zippe , in which even more pieces of the new mineral were later discovered. The label of the second sample only stated that it was a "tomback brown, problematic fossil" and that it was "crystallized in six-sided tablets". However, it was known that the material came from Sankt Joachimsthal (today Jáchymov ) in the Czech part of the Ore Mountains .

Together with Karl August Neumann and Zippe, Haidinger proposed the name sternbergite for the new mineral, in honor of the founder of the National Museum, Count Kaspar Maria von Sternberg .

classification

Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the sternbergite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with metal: S, Se, Te ≈ 1: 1", where it together with argentopyrite , cubanite , enargite the "enargite series" with the system no. II / C.14 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 sternbergite in the category of "Metal sulfides, M: S = 1: 1 (and similar)". However, this is further subdivided according to the predominant metals in the compound, so that the mineral can be found in the sub-section "with zinc (Zn), iron (Fe), copper (Cu), silver (Ag) etc." according to its composition , where only together with argentopyrite the "Sternbergite group" with the system no. 2.CB.65 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the sternbergite to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here it can be found together with picotpaulite in the unnamed group 02.09.12 within the subsection “Sulphides - including selenides and tellurides - with the composition A _m B _n X _p , with (m + n): p = 1: 1”.

Crystal structure

Sternbergite crystallizes in the orthorhombic crystal system in the space group Ccme (space group no. 64, position 2) with the lattice parameters a = 6.615 Å , b = 11.639 Å and c = 12.693 Å as well as eight formula units per unit cell . Template: room group / 64.2

Modifications and varieties

Sternbergite is dimorphic to argentopyrite . The two minerals are based on their composition and only differ in their crystallographic space group and the lattice parameters.

Education and Locations

Sternbergite forms hydrothermally together with other silver-containing sulfosalts and in sulfidic cobalt-nickel-silver accumulations. It is associated with stephanite , acanthite , prostite , pyrargyrite , argentopyrite , xanthoconite , pyrite , galena , sphalerite , dolomite , calcite and quartz .

So far (as of December 2010) 51 locations of sternbergite are known. In addition to its type locality , the mineral was found in Beaverdell and Itchen Lake in Canada , Hulun Buir and Wannian in China , Châteauneuf-du-Faou and La-Croix-aux-Mines in France , Wieden , Waidhaus , Nieder-Beerbach , Sankt Andreasberg, among others , Meschede and several places in the Ore Mountains in Germany , Márianosztra in Hungary , Aomori , Suzuyama and Miyazaki in Japan , Pachuca de Soto and Temascaltepec in Mexico , Djebel Sarhro and Djebel Siroua in Morocco , Kongsberg and Hemnes in Norway , Celendin in Peru , Chiuzbaia in Romania , the Primorye and Kamchatka regions in Russia , Hiendelaencina in Spain , Boliden and Hällefors in Sweden and the US states of Arizona , California , Colorado , Nevada and New Mexico .

literature

W. Haidinger: On Sternbergite, a New Mineral Species . In: The Edinburgh Journal of Science . tape 7 , 1827, pp. 242–244 (English, rruff.info [PDF; 223 kB ; accessed on December 11, 2018]).
W. Haidinger: Description of sternbergite, a new mineral species . In: Transactions of the Royal Society of Edinburgh . tape 11 , 1828, pp. 1–7 (English, rruff.info [PDF; 495 kB ; accessed on December 11, 2018]).
Star mountainite . 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; 87 kB ; accessed on December 11, 2018]).

Web links

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

Mineral Atlas: Sternbergite (Wiki)
Mindat - Sternbergite (English)
RRUFF Database-of-Raman-spectroscopy - Sternbergite (English)
American-Mineralogist-Crystal-Structure-Database - Sternbergite (English)

Individual evidence

↑ ^a ^b Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties . 6th completely revised and supplemented edition. Weise, Munich 2014, ISBN 978-3-921656-80-8 .

^ Mineral Atlas : Sternbergite

↑ ^a ^b ^c ^d 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. 83 .

↑ Webmineral - Sternbergite (English)

↑ ^a ^b The former name of this room group was Ccmb .

↑ ^a ^b ^c ^d Sternbergite . 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; 87 kB ; accessed on December 11, 2018]).

↑ ^a ^b Wilhelm Haidinger : Ueber den Sternbergit, a new mineral species (excerpt from the Edinb. Journ. Of Science T. VII. 242) . In: JC Poggendorff (Ed.): Annals of Physics and Chemistry . tape 11 . Verlag by Joh.Ambrosius Poggendorff, Leipzig 1827, p. 483–486 ( limited preview in Google Book search).

↑ Find location list for Sternbergite in the Mineralienatlas and Mindat

[Lapis-1] Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties . 6th completely revised and supplemented edition. Weise, Munich 2014, ISBN 978-3-921656-80-8 .

[Mineralienatlas-2] Mineral Atlas : Sternbergite

[StrunzNickel-3] 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. 83 .

[Webmineral-4] Webmineral - Sternbergite (English)