Tellurobismutite
| Tellurobismutite | |
|---|---|
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|
| General and classification | |
| other names |
Telluric bismuth, telluric bismuth, telluric bismuth |
| chemical formula | Bi 2 Te 3 |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.DC.05 ( 8th edition : II / C.03a) 11/02/07/02 |
| Crystallographic Data | |
| Crystal system | trigonal |
| Crystal class ; symbol | Please complete |
| Space group | R 3 m (No. 160) |
| Lattice parameters | a = 4.43 Å ; c = 29.91 Å |
| Formula units | Z = 3 |
| Physical Properties | |
| Mohs hardness | 1.5-2 |
| Density (g / cm 3 ) | calculated: 7.918 measured: 7.815 |
| Cleavage | Please complete |
| colour | White |
| Line color | lead gray |
| transparency | opaque (opaque) |
| shine | strong white metallic sheen |
| Other properties | |
| Special features | Sulfur contamination possible |
Tellurobismutite is a rather seldom occurring mineral from the mineral class of " sulfides and sulfosalts " with the chemical composition Bi 2 Te 3 and thus chemically corresponds to the compound bismuth telluride .
Tellurobismutite crystallizes in the trigonal crystal system and is often found in the form of leafy to tabular crystals with a hexagonal habit and a maximum of a few millimeters in diameter. The mineral is often associated with gold , quartz , galena , chalcopyrite and calaverite , tetradymite and backlid . Tellurobismutite is opaque and shows a metallic sheen on the surface of the white to lead-gray crystals .
Etymology and history
Tellurobismutite was named after the chemical composition of the mineral from bismuth and tellurium .
classification
In the old systematics of minerals according to Strunz (8th edition) tellurobismutite was still in the section “II / C. Sorted one "where he, together with the 1991 discredited: sulphides with M: S <1 Csiklovait and tetradymite and wehrlite the tetradymite series within the tetradymite-Ikunolith-Paraguanajuatit group was formed.
Since the 9th edition of Strunz's mineral systematics, the mineral has belonged to the department of “Metal sulfides with M: S = 3: 4 and 2: 3” and there to the subdivision “M: S variable”. It forms there, together with Kawazulith , Paraguanajuatit , Skippenit , Tellurantimon and tetradymite the Tetradymitgruppe .
The classification of minerals by Dana also assigns the Tellurobismutit in the class of the sulphides and there with tetradymite , Tellurantimon , Paraguanajuatit , Kawazulith , Skippenit and Vihorlatit in the " Tetradymitgruppe " within the department of "sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 2: 3 “a.
Crystal structure
Tellurobismutite crystallizes in the trigonal crystal system in the space group R 3 m (space group no. 160) with the lattice parameters a = 4.43 and c = 29.91 Å as well as three formula units per unit cell .
Education and Locations
Since tellurium shows the highest affinity for gold of all elements , tellurobismutite is often formed by hydrothermal processes in connection with gold deposits. It often forms parageneses with numerous other bismuth tellurides, bismuth tellurium sulfides, lead and gold tellurides, and solid gold. Mention may be made here Rucklidgeit , Calaverit , tetradymite , Tsumoit , Nagyagit and altaite . In addition, associations with the widespread sulfides galena and chalcopyrite as well as the gangue minerals quartz and calcite are common.
The three co- type localities of the mineral are the Mosnap mine as part of the Moisesberg mines in Fyresdal commune in Telemark , Norway , the Boly Field gold mine at Dahlonega in Lumpkin County , Georgia, and the Little Mildred mine in the Sylvanite District in Hidalgo County , New Mexico in the USA .
As a rather rare mineral formation, tellurobismutite is distributed all over the world, but is mostly spatially limited and only available in small quantities. Around 300 sites are known to date (as of 2020). The mineral could be found in Egypt , Argentina , Armenia , Azerbaijan , Australia , Belgium , Brazil , Bulgaria , Burkina Faso , China , the Dominican Republic , Fiji , Finland , France , Greece , Guyana , Japan , Cambodia , Canada , Kazakhstan , Kyrgyzstan , Mali , Mongolia , North Korea , Norway , Papua New Guinea , the Philippines , Poland , Romania , Russia , Saudi Arabia , Sweden , Zimbabwe , Slovakia , Spain , South Africa , Tajikistan , Thailand , the Czech Republic , Ukraine , Hungary , Uzbekistan , the United Kingdom and the United States .
The only previously described find from Austria is still considered unsafe and comes from the Rellstal in the municipality of Vandans in Vorarlberg .
use
Since tellurium and selenium are obtained industrially exclusively from by-products of the large-scale electrolytic copper and nickel production, tellurobismutite is of no importance as a tellurium ore. Due to its rarity compared to other bismuth-containing minerals, it does not play any economic role as bismuth ore. Levels of the mineral are only sought after by collectors.
See also
literature
- J. Esmark: XIV. Description of a New Ore of Tellurium. In: Transactions of the Geological Society of London . S1-3, no. 1 , January 1, 1816, p. 413–414 , doi : 10.1144 / transgsla.3.413 (first description of tellurium bismuthite as tellurium bismuth).
- J. Berzelius: Undersökning af tvenne i K. Vet. Academinens Mineralsamling befintliga Mineralier . In: Kongliga Vetenskaps-Academiens Handlingar . 1823, p. 183-189 (description as tellurium-bound bismuth).
- Paul W. Lange: A comparison between Bi 2 Te 3 and Bi 2 Te 2 . In: Natural Sciences . tape 27 , no. 8 , 1939, pp. 133-134 , doi : 10.1007 / BF01490284 .
- Clifford Frondel: Redefinition of tellurobismuthite and vandiestite . In: American Journal of Science . tape 238 , no. December 12 , 1940, p. 880-888 , doi : 10.2475 / ajs.238.12.880 .
- C. Palache, H. Berman, C. Frondel: The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume I: Elements, Sulfides, Sulfosalts, Oxides . 7th edition, revised and expanded. John Wiley and Sons, Inc., New York 1944, p. 160-161 .
- AWG Kingsbury: Tellurbismuth and meneghinite, two minerals new to Britain . In: Mineralogical Magazine and Journal of the Mineralogical Society . tape 35 , no. 270 , June 1965, p. 424-426 , doi : 10.1180 / minmag.1965.035.270.19 .
- Nigel J. Cook, Cristiana L. Ciobanu, Thomas Wagner, Christopher J. Stanley: Minerals of the system Bi-Te-Se-S related to the tetradymite archetype: review of classification and compositional variation . In: The Canadian Mineralogist . tape 45 , no. 4 , August 1, 2007, p. 665-708 , doi : 10.2113 / gscanmin.45.4.665 .
Web links
- Tellurobismutite . In: Mineralienatlas , accessed on April 17, 2020.
- Tellurobismuthite Mineral Data . In: Mineralogy Database - webmineral.com , accessed April 17, 2020.
Individual evidence
- ↑ a b c d e f g h Tellurobismuthite. In: mindat.org . Hudson Institute of Mineralogy, accessed April 17, 2020 .
- ↑ a b Rösler, Hans Jürgen : Textbook of Mineralogy . 3. Edition. VEB German publishing house for basic industry , Leipzig 1984, p. 339 .