Toyohait
| Toyohait | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA 1989-007 |
| chemical formula | Ag 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) 02.10.03.02 |
| Crystallographic Data | |
| Crystal system | tetragonal |
| Crystal class ; symbol | tetragonal-dipyramidal; 4 / m |
| Room group (no.) | I 4 1 / a (No. 88) |
| Lattice parameters | a = 7.46 Å ; c = 10.80 Å |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | 4th |
| Density (g / cm 3 ) | 4.94 |
| Cleavage | microcrystalline aggregates and grains |
| colour | brownish gray |
| Line color | Please complete |
| transparency | opaque |
| shine | Metallic luster |
Toyohait is a very rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the tetragonal crystal system with the composition Ag 2 FeSn 3 S 8 , so from a chemical point of view it is a silver - iron - tin sulfide.
Toyohaite could only be found in the form of microcrystalline aggregates up to about 200 μm or in individual grains with a diameter of about 1–30 μm. It is opaque and has a metallic sheen . Its color appears brownish-gray in the reflected light. Compared to rhodostannite and hocartite , however, it is a little more brown.
Etymology and history
Toyohait was first discovered in the "Toyoha Mine" near Sapporo on the Japanese island of Hokkaidō and scientifically described in 1991 by J. Yajima, E. Ohta and Y. Kanazawa, who named the mineral after its type of locality .
Type material of the mineral was deposited in the Geological Museum of the Geological Survey of Japan in Sapporo.
classification
Already in the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the toyohaite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with the molar ratio of metal (M): sulfur (S) (selenium, tellurium) ) ≈ 1: 1 ", where together with barquillite , briartite , černýite , famatinite , ferrokësterite , hocartite , kësterite, kuramite , luzonite , permingeatite , petrukite , pirquitasite , rhodostannite , sakuraiite , stannite and velikite the" systemic group " 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 Toyohaite to the class of “sulfides and sulfosalts”, but there in the department of “metal sulfides with the substance ratio M: S = 3: 4 and 2: 3 “. This section is further subdivided according to the exact molar ratio, so that the mineral can be found according to its composition in the sub-section "M: S = 3: 4", where, together with rhodostannite, 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 Toyohaite to the class of "sulfides and sulfosalts" and there in the department of "sulfide minerals". Here it can be found together with rhodostannite in the unnamed group 02.10.03 within the subsection " Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 3: 4 ".
Education and Locations
Toyohaite is found in massive pyrite - sphalerite ore veins in basalts from the Miocene. The accompanying minerals include Berndtite , Herzenbergite , Hocartite, Rhodostannite and Teallite .
Apart from its type locality “Toyoha Mine” in Japan, Toyohait has so far (as of 2012) only been detected in the Argentinian province of Jujuy , more precisely in the “Oploca Mine” of the “Pirquitas” deposit in the Rinconada department .
Crystal structure
Toyohait crystallizes tetragonally in the space group I 4 1 / a (space group no. 88) with the lattice parameters a = 7.46 Å and; c = 10.80 Å and 2 formula units per unit cell .
See also
Web links
- Mineral Atlas: Toyohait (Wiki)
Individual evidence
- ↑ 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. 95 .
- ↑ a b c Webmineral - Toyohaite
- ^ A b John L. Jambor, Jacek Puziewicz: New Mineral Names - Toyohaite , in: American Mineralogist , Volume 77 (1992), pp. 1116–1121 ( PDF 641 kB )
- ^ Mindat - Toyohaite