Tennantite
| Tennantite | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula | Cu 12 [S | (AsS 3 ) 4 ] |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.GB.05 ( 8th edition : II / C.11) 03.03.06.02 |
| Similar minerals | Tetrahedrite , Freibergite |
| Crystallographic Data | |
| Crystal system | cubic |
| Crystal class ; symbol | cubic-hexakistrahedral; 4 3 m |
| Space group | I 4 3 m (No. 217) |
| Lattice parameters | a = 10.23 Å |
| Formula units | Z = 2 |
| Frequent crystal faces | {211}, {100}, {110} |
| Physical Properties | |
| Mohs hardness | 3 to 4.5 |
| Density (g / cm 3 ) | 4.6 to 4.7 |
| Cleavage | no |
| Break ; Tenacity | shell-like |
| colour | steel gray to black |
| Line color | depending on the zinc content, black-gray to brown to vermilion |
| transparency | opaque (opaque) |
| shine | Metallic luster |
| Crystal optics | |
| Refractive index | n > 2.72 |
| Birefringence | none, as it is optically isotropic |
Tennantite , also known under the outdated mining name arsenic pale ore , is a frequently occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the cubic crystal system with the chemical composition Cu 12 [S | (AsS 3 ) 4 ] and develops mostly tetrahedral crystals similar to the tetrahedral , but granular or massive aggregates in a metallic, shiny steel gray. The mineral is actually opaque, but very fine splinters can be reddish translucent.
Tennantit forms with tetrahedrite ( Antimonfahlerz one as) Fahlerze called mixed batch .
Etymology and history
According to the researchers, pale ores were already known in antiquity, but were not scientifically considered and described by Georgius Agricola until the Middle Ages . The arsenic -ahler ore tennantite was described in 1819 by Phillips & Phillips, who named it after the English chemist Smithson Tennant (1761-1815). Since material from Redruth in the south-west of the English county of Cornwall was used for the analyzes , this site is considered to be a type locality of Tennantite.
The name Binnit (after Des Cloizeaux ) is a synonym for the extensive and apparently holohedral tennantite crystals found in the Lengenbach mine in the Swiss Binntal .
The name Julianite was given in 1892 by James Dwight Dana .
classification
In the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the tennantite belonged to the mineral class of "sulfides and sulfosalts" and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 together with argentotennantite , chaméanite , giraudite , goldfieldite , Freibergite , Hakit , Mgriit and tetrahedrite the "tetrahedrite group" with the system no. II / C.11 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 tennantite to the class of "sulfides and sulfosalts", but in the section of "sulfarsenides, sulfantimonides, sulfbismutides" . This is further subdivided according to the type of linkage of the compound components, so that the mineral can be found in the sub-section of "Island sulfarsenides (Neso-sulfarsenides) etc., with additional sulfur (S)", where the name is given by the "Tennantite group" with the system no. 2.GB.05 and the other members Argentotennantit, Argentotetraedrit , Freibergit, Galkhait forms Giraudit, Goldfieldit, Hakit and tetrahedrite.
The systematics of minerals according to Dana also assigns the tennantite to the class of "sulfides and sulfosalts" and there in the department of "sulfosalts". Here it is together with tetrahedral, Freibergit, Hakit, Giraudit, Goldfieldit and Argentotennantit in the "Tetrahedrite group" with the system no. 03.03.06 within the subdivision of " Sulphosalts with the ratio 3 <z / y <4 and the composition (A +) i (A2 +) j [ByCz], A = metals, B = semi-metals, C = non-metals ".
Crystal structure
Tennantite crystallizes cubically in the space group I 4 3 m (space group no. 217) with the lattice parameter a = 10.23 Å and two formula units per unit cell .
Education and Locations
Tennantite forms hydrothermally in Greisen or through contact metamorphosis . Accompanying minerals ( parageneses ) are mainly tetrahedrite and Freibergite , to which tennantite also has a close structural relationship, but also many other copper , lead , zinc and silver-containing sulfides and sulfosalts such as bornite and pyrite , as well as barite , Calcite , dolomite , fluorite , quartz and siderite . Tennantite can contain up to 15% silver and zinc on the copper position in the crystal lattice .
Tennantite has been detected at over 1200 sites worldwide so far (as of 2010), including in Afghanistan , Egypt , several regions of Argentina , Armenia , some regions of Australia , Bolivia , Brazil , Bulgaria , Chile , China , Germany , Ecuador , Eritrea , on the Fiji Islands , in Finland , France , Greece , Greenland , India , Indonesia , Iran , Ireland , Italy , Japan , Canada , on the Channel Island of Sark , Kazakhstan , Democratic Republic of the Congo , in Kosovo , in Kyrgyzstan , Croatia , Morocco , Macedonia , Mexico , Mongolia , Namibia , New Zealand , Norway , Oman , Austria , Papua New Guinea , Peru , the Philippines , Poland , Portugal , Romania , Russia , Sweden , Switzerland , Serbia , Slovakia , Slovenia , Spain , South Africa , South Korea , the Czech Republic , Tunisia , Turkey , Ukraine , Hungary , the United Kingdom and the United States of America (USA).
See also
literature
- Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 433 (first edition: 1891).
- Tennantite . 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; 114 kB ; accessed on September 20, 2017]).
- Petr Korbel, Milan Novák: Mineral Encyclopedia (= Villager Nature ). Nebel Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 28 .
Web links
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. 122 .
- ↑ Tennantite at mindat.org (Eng.)
- ↑ GeoMuseum TU Freiberg - Tetrahedron (and Tennantite)
- ↑ Mineral Atlas: Binnite (after Des Cloizeaux)
- ↑ VDC Daltry: Annales de la Société Géologique de Belgique: The Type Mineralogy of Africa: Zaire (Mineral Description Julienit with confusion Note = to Julianit Tennantit, p.10)
- ↑ Mindat - Localities for Tennantite