Rhodostannite

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Rhodostannite
General and classification
other names

IMA1968-018

chemical formula Cu 2 FeSn 3 S 8
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.DA.10 ( 8th edition : II / C.06)
02.10.03.01
Crystallographic Data
Crystal system tetragonal
Crystal class ; symbol tetragonal-dipyramidal; 4 / m
Room group (no.) I 4 1 a (No. 88)
Lattice parameters a  = 7.31  Å ; c  = 10.33 Å
Formula units Z  = 2
Physical Properties
Mohs hardness Please complete!
Density (g / cm 3 ) calculated: 4.79
Cleavage Please complete!
colour reddish to reddish brown
Line color Please complete!
transparency opaque
shine Metallic luster

Rhodostannite is a very rare mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the tetragonal crystal system with the chemical composition Cu 2 FeSn 3 S 8 , so from a chemical point of view it is a copper - iron - tin sulfide.

Rhodostannite is opaque in every form and has so far only been found in the form of very fine-grained, porous masses of reddish to reddish-brown, metallic shining color.

Etymology and history

Rhodostannite was first discovered near Vila Apacheta in the Bolivian province of Rafael Bustillo and described in 1968 by G. Springer, who named the mineral because of its reddish color after the ancient Greek word τὸ ῥόδον for rose and its tin content after its Latin name stannum .

classification

In the meanwhile outdated, but still in use 8th edition of the mineral classification according to Strunz , the rhodostannite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with the molar ratio of metal: sulfur, selenium, tellurium ≈ 1: 1", where he together with Barquillit , Černýit , Famatinit , Ferrokësterit , Hocartit , Kësterit , Kuramit , Luzonit , Briartit , Permingeatit , Petrukit , Pirquitasit , Sakuraiit , Stannit , Toyohait and Velikit the "Stannit-Gruppe" with the system no. II / C.06 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 assigns rhodostannite to the class of “sulfides and sulfosalts”, but in the category of “metal sulfides with M: S = 3 : 4 and 2: 3 “. This department is also further subdivided according to the exact molar ratio so that the mineral can be found according to its composition in the subdivision "M: S = 3: 4", where together with Toyohait the "rhodostannite group" with the system no . 2.DA.10 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns rhodostannite to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here he can be found together with Toyohait in the unnamed group 02.10.03 within the subdivision " Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 3: 4 ".

Education and Locations

Rhodostannit formed as a weathering product of Stannit and comes in accordance with this, but also with pyrite associated ago.

So far (as of 2012) around 10 locations for rhodostannite are known worldwide. In addition to its type locality Vila Apacheta in the province of Rafael Bustillo (Department Potosí), the mineral appeared in Bolivia in the "San José Mine" near Oruro and the "Santa Cruz Mine" near Poopó in the Oruro department.

Other sites are found in the Argentinian province of Jujuy (Oploca Mine), on the Japanese islands of Hokkaidō (Toyoha Mine) and Shikoku (Besshi Mine) and in the US states of Arizona (Campbell Mine, Bisbee) and Nevada (Dean Mine).

Crystal structure

Rhodostannite crystallizes tetragonally in the space group I 4 1 a (space group no. 88) with the lattice parameters a  = 7.31  Å and c  = 10.33 Å as well as 2 formula units per unit cell .

See also

literature

Web links

Individual evidence

  1. ↑ a b c d e 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.  94 .
  2. ↑ Webmineral - Rhodostannite.
  3. ↑ a b Rhodostannite. In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols: Handbook of Mineralogy, Mineralogical Society of America. 2001 ( handbookofmineralogy.org PDF; 61.1 kB).
  4. ↑ Mindat - Rhodostannite.