Tetrahedrite

Tetrahedral (Zn)
Tetrahedron (steel-gray tetrahedron) and pyrite (small gold-colored crystals) from Clausthal-Zellerfeld , Lower Saxony, Germany (field of view 3 cm)
General and classification
other names	dark pale ore Black ore Antimony ore
chemical formula	Cu 6 (Cu 4 Zn 2 ) Sb 4 S 13 Cu 10 (Fe, Zn) 2 Sb 4 S 13 Cu 12 [S | (SbS 3 ) 4 ]
Mineral class (and possibly department)	Sulfides and sulfosalts
System no. to Strunz and to Dana	2.GB.05 ( 8th edition : II / B.05) 03.03.06.01
Crystallographic Data
Crystal system	cubic
Crystal class ; symbol	cubic-hexakistrahedral; 4  3  m
Space group	I 4 3 m (No. 217)
Lattice parameters	a  = 10.36  Å
Formula units	Z  = 2
Twinning	after {111}
Physical Properties
Mohs hardness	3 to 4.5
Density (g / cm 3 )	4.97
Cleavage	no
Break ; Tenacity	shell-like
colour	steel gray to black, translucent in very thin layers of cherry red
Line color	grey black
transparency	opaque
shine	Metallic luster
Crystal optics
Refractive index	n  > 2.72
Other properties
Chemical behavior	soluble in nitric acid and aqua regia

Tetrahedrite , more precisely tetrahedrite (Zn) since 2019 , is a frequently occurring mineral from the mineral class of " sulfides and sulfosalts " with the idealized chemical composition Cu ₆ (Cu ₄ Zn ₂ ) Sb ₄ S ₁₃ . Structurally, tetrahedrite is one of the sulfosalts rich in copper and silver .

Tetrahedron crystallizes in the cubic crystal system and develops mostly steel-gray to black crystals in tetrahedral shape, but also occurs in the form of granular to coarse mineral aggregates .

With tennantite and Freibergite , tetrahedrite forms a seamless mixed series , the mixed crystals and end links of which are grouped together with other related minerals under the name Fahlerz .

Etymology and history

Tetrahedrite was originally known under the mining name of dark pale ore or black ore (in contrast to light pale ore tennantite ). Since the pale ores are different minerals, a distinction was made later according to their composition and tetrahedrite was accordingly referred to as antimony pale ore .

The mineral was given its name tetrahedrite, which is still valid today, in 1845 from Wilhelm von Haidinger , who named it after its frequently occurring and therefore characteristic crystal form.

classification

In the outdated 8th edition of the mineral classification according to Strunz , tetrahedron belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with M: S = 1: 1", where it together with Freibergite and Tennantite as well as with the formerly known as Annivite well-known and in 2008 discredited bi-tetrahedron the "Tennantit series" with the system no. II / B.05 .

In the Lapis mineral directory according to Stefan Weiß, which, out of consideration for private collectors and institutional collections, is still based on this old, but revised and updated, systematic form of Karl Hugo Strunz , the mineral received the system and mineral number. II / C.11-40 . In the “Lapis system” this corresponds to the section “Sulphides with metal: S, Se, Te ≈ 1: 1”, where tetrahedrite is named after the “tetrahedrite group” with the other members annivite , argentotennantite , argentotetraedrite, chaméanite , Freibergite , Giraudit , Goldfieldit , Hakit , Mgriit and Tennantit forms (as of 2018).

The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and updated by the International Mineralogical Association (IMA) until 2009, classifies the tetrahedrite in the newly defined division of “sulfarsenides, sulfantimonides and sulfbismutides”. This is further subdivided according to the crystal structure, so that the mineral can be found according to its structure in the sub-section "Island sulfarsenides (Neso sulfarsenides) etc., with additional sulfur (S)", where it can be found together with argentotennantite , argentotetraedrite , Freibergit , Giraudit , Goldfieldit , Hakit and Tennantit the "Tennantitgruppe" with the system no. 2.GB.05 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the tetrahedrite to the class of "sulphides and sulphosalts" and there in the category of "sulphide minerals". Here he is the namesake of the "[[Systematics of minerals according to Dana / Sulfide # 03.03.06 Tetrahedrite group (isometric: I43m) | Tetrahedrite group (isometric: I 4 3 m )]]" with the system no. 03.03.06 and the other members Tennantit, Freibergit, Hakit, Giraudit, Goldfieldit and Argentotennantit within the sub-section “Sulphosalts with the ratio 3 <z / y <4 and the composition (A ⁺ ) _i (A ²⁺ ) _j [B _y C _z ], A = metals, B = semimetals, C = non-metals ”.

In 2019, the tetrahedron group was redefined after a resolution by the IMA / CNMNC (internal entry number of the IMA: 18-K). The general formula of the chemical composition is
^{M (2)} A ₆ ^{M (1)} (B ₄ C ₂ ) _Σ6 ^{X (3)} D ₄ ^{S (1)} Y ₁₂ ^{S (2)} Z (Z = 2). The individual placeholders can be filled with the following elements:

• A = Cu ⁺ , Ag ⁺ , □
• B = Cu ⁺ , Ag ⁺
• C = Zn ²⁺ , Fe ²⁺ , Hg ²⁺ , Cd ²⁺ , Mn ²⁺ , Cu ²⁺ , Cu ⁺ , Fe ³⁺
• D = Sb ³⁺ , As ³⁺ , Bi ³⁺ , Te ⁴⁺
• Y = S ²⁻ , Se ²⁻
• Z = S ²⁻ , Se ²⁻ , □

On the basis of the A, B, D and Y constituents, the group is further divided into the Tetrahedrite, Tennantite, Freibergite, Hakit and Giradite series, with the type of dominant C constituent using a suffix, separated by hyphens and enclosed in parentheses. The tetrahedrite group currently contains 11 minerals recognized by the IMA: argentotennantite (Zn) , argentotetraedrite (Fe) , kenoargentotetraedrite (Fe) , giraudite (Zn) , goldfieldite, hakite (Hg) , rozhdestvenskayaite (Zn) , Tennantite (Fe) , tennantite (Zn) , tetrahedral (Fe) and tetrahedral (Zn). In addition, Annivite is formally discredited.

Crystal structure

Tetrahedron crystallizes cubically in the space group I 4 3 m (space group no. 217) with the lattice parameter a  = 10.36  Å and 2 formula units per unit cell .

properties

Tetrahedral overgrown with chalcopyrite ( copper pyrites )

In very thin layers such as thin sections , especially arsenic-containing tetrahedron is cherry-red translucent with a refractive index of n _{852 nm}  = 2.92 to 3.12. For this reason, the line color can also be changed. The initially black line turns red-brown when rubbed. A common chalcopyrite coating can simulate a yellow color.

In contrast to the very similar-looking tennantite , freshly broken tetrahedrite shows a lighter fracture surface, which, however, turns black after a while.

Tetrahedrite dissolves in nitric acid with the excretion of sulfur and antimony (III) oxide . It decomposes completely in aqua regia .

The mineral is easily melted in front of the soldering tube , forming a gray ball. After roasting , it reacts with copper and usually also with iron .

morphology

Penetrating twin from Colquechaca, Chayanta, Potosí, Bolivia

Tetrahedron often forms extensive and well-developed crystals with a clear to almost perfect tetrahedral shape . Also penetration twins on {111} are commonly found. In the case of ideal penetration, the tips of one tetrahedron look out a little in the middle from the surfaces of the other tetrahedron.

Education and Locations

Tetrahedrite (approx. 1.5 cm large crystal) with pink rhodochrosite and small quartz needles (background)

Usually Tetraedrit forms in hydrothermal low to moderate passages , but also in kontaktmetamorphen deposits , where the mineral is, inter alia, arsenopyrite , Akanthit , barite , bornite , calcite , chalcopyrite , dolomite , fluorite , galena , pyrite , quartz , siderite and sphalerite associated occurs.

As a frequent mineral formation, tetrahedrite can be found at many sites, with almost 6000 sites being documented so far (as of 2020).

In Germany, the mineral has so far occurred in some mines near Freudenstadt in Baden-Württemberg, in some mines and quarries in the Bavarian Fichtel Mountains and the Upper Palatinate , in many mines near Sankt Andreasberg , Clausthal-Zellerfeld and Bad Lauterberg and other places in the Harz Mountains of Hesse to Saxony-Anhalt as well as in many mines and collieries near Fischelbach and in the Bensberg ore district in North Rhine-Westphalia. Tetrahedrite was also found in many places in the Eifel and Siegerland in Rhineland-Palatinate and in the Saxon Ore Mountains .

In Austria, tetrahedron was found mainly in Carinthia , the Salzburg region , Styria and Tyrol .

In Switzerland, the mineral is known from the Val d'Anniviers in the canton of Valais . Tetrahedrite was also found in some pits in the canton of Graubünden .

Known for the extraordinary tetrahedrite finds of Anzen and Irazein in the French part of the Pyrenees , where crystals up to 25 cm in size were unearthed. Well-developed crystal aggregates up to about 7 cm in size were found in the “Mercedes Mine” near Huallanca in the Peruvian region of Huánuco .

Other sites are found in Egypt , Algeria , Antarctica , Argentina , Armenia , Ethiopia , Australia , Belgium , Bolivia , Bosnia and Herzegovina , Brazil , Bulgaria , Burkina Faso , Chile , China , Germany , Ecuador , Eritrea , Fiji , Finland , France , French Guinea , Ghana , Greece , Greenland , Honduras , India , Indonesia , Iran , Ireland , Isle of Man , Italy , Japan , Canada , Channel Islands , Kazakhstan , Kyrgyzstan , Colombia , North and South Korea , Kosovo , Cuba , Madagascar , Morocco , Mexico , Mongolia , Namibia , New Zealand , Netherlands , North Macedonia , Norway , Austria , Papua New Guinea , Peru , Philippines , Poland , Portugal , Romania , Russia , Saudi Arabia , Sweden , Switzerland , Serbia , Zimbabwe , Slovakia , Slovenia , Spain , South Africa , Tajikistan , Taiwan , Czech Republic , Tunisia , Turkey , Ukraine , Hungary , Uzbekistan , Venezuela , the United Kingdom (UK) and the United States of America (USA).

Tetrahedrite was also found in rock samples from the Juan de Fuca Ridge , more precisely from the Escanaba Valley of the Gorda Ridge in the Pacific Ocean .

use

Like all Pale ores , the tetrahedron is also an important ore for the extraction of copper , the proportion of which is around 34.8% for pure tetrahedrite.

See also

• List of minerals

literature

• Willhelm Haidinger: Handbook of determining mineralogy . Braumüller and Seidel, Vienna 1845, p. 563-570 , Second Class: Geogenides. XIV. Order. Shine. I. Dystom gloss. Tetrahedron ( rruff.info [PDF; 451 kB ; accessed on January 1, 2020]).
• Tetrahedrite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 (English, handbookofmineralogy.org [PDF; 101 kB ; accessed on January 1, 2020]).
• Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 433-435 (first edition: 1891).
• Martin Okrusch, Siegfried Matthes: Mineralogy. An introduction to special mineralogy, petrology and geology . 7th, completely revised and updated edition. Springer, Berlin [a. a.] 2005, ISBN 3-540-23812-3 , pp. 43 .

Web links

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

• Mineral Atlas: Tetrahedrite (Wiki)
• Tetrahedrite search results. In: rruff.info. Database of Raman spectroscopy, X-ray diffraction and chemistry of minerals (RRUFF)(English). 
• American-Mineralogist-Crystal-Structure-Database - Tetrahedrite. In: rruff.geo.arizona.edu. (English). 

Individual evidence

1. ↑ ^{a b} Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: November 2019. (PDF 1720 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, November 2019, accessed January 2, 2020 .  
2. ↑ ^{a b} Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties. Status 03/2018 . 7th, completely revised and supplemented edition. Weise, Munich 2018, ISBN 978-3-921656-83-9 .
3. ↑ ^{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.  122 (English).
4. ↑ ^{a b} David Barthelmy: Tetraehedrite Mineral Data. In: webmineral.com. Retrieved January 1, 2020 .  
5. ^ Willhelm Haidinger: Handbook of determining mineralogy . Braumüller and Seidel, Vienna 1845, p. 563-570 , Second Class: Geogenides. XIV. Order. Shine. I. Dystom gloss. Tetrahedron ( rruff.info [PDF; 451 kB ; accessed on January 1, 2020]).
6. ↑ Yves Moëlo, Emil Makovicky, Nadejda N. Mozgova, John Leslie Jambor , Nigel Cook, Allan Pring, Werner Paar, Ernest H. Nickel , Stephan Graeser, Sven Karup-Møller, Tonči Balic-Žunic, William G. Mumme, Filippo Vurro , Dan Topa, Luca Bindi, Klaus Bente, Masaaki Shimizu: Sulfosalt systematics: a review. Report of the sulfosalt sub-committee of the IMA Commission on Ore Mineralogy . In: European Journal of Mineralogy . tape 20 , 2008, p. 28 , doi : 10.1127 / 0935-1221 / 2008 / 0020-1778 (English, rruff.info [PDF; 485 kB ; accessed on January 2, 2020]).
7. ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1816 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed January 1, 2020 .  
8. ↑ Ritsuro Miyawaki, Frédéric Hatert, Marco Pasero, Stuart J. Mills: IMA Commission on New Minerals, Nomenclature and Classification (CNMNC). NEWSLETTER 49 . In: European Journal of Mineralogy . tape 31 , no. 5–6 , 2019, pp. 1099–1104 , doi : 10.1127 / ejm / 2019 / 0031-2861 (English, cnmnc.main.jp [PDF; 287 kB ; accessed on January 2, 2020]).
9. ↑ Localities for Tetraedrite. In: mindat.org. Hudson Institute of Mineralogy, accessed January 1, 2020 .  
10. ↑ Petr Korbel, Milan Novák: Mineral Encyclopedia (=  Dörfler Natur ). Edition Dörfler im Nebel-Verlag, Eggolsheim 2002, ISBN 978-3-89555-076-8 , p. 29 .
11. ↑ Pictures with cast tetrahedrites from the Mercedes Mine, Huallanca, District Huallanca, Province Bolognesi, Áncash, Peru. In: mindat.org. Hudson Institute of Mineralogy, accessed January 1, 2020 .  
12. ↑ Find location list for tetrahedrite in the Mineralienatlas and Mindat , accessed on January 1, 2020.
13. ^ Stefan Schorn and others: Escanaba valley location. In: mineralienatlas.de. Mineral Atlas , accessed January 1, 2020 .