Algodonite
| Algodonite | |
|---|---|
 |
|
| General and classification | |
| chemical formula |
|
|
Mineral class (and possibly department) |
Sulphides and sulphosalts - alloys and alloy-like compounds |
|
System no. to Strunz and to Dana |
2.AA.05 ( 8th edition : II / A.01) 02.01.01.01 |
| Crystallographic Data | |
| Crystal system | hexagonal |
| Crystal class ; symbol | dihexagonal-dipyramidal; 6 / m 2 / m 2 / m |
| Space group | P 6 3 / mmc (No. 194) |
| Lattice parameters | a = 2.588 Å ; c = 4.226 Å |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | 4 (VHN 100 = 245–302) |
| Density (g / cm 3 ) | measured: 8.38; calculated: 8.72 |
| Cleavage | is missing |
| Break ; Tenacity | slightly mussel-like |
| colour | steel gray to silver white |
| Line color | Please complete |
| transparency | opaque |
| shine | Metallic sheen, turning matt gray over time in the air |
| Crystal optics | |
| Pleochroism | strong |
Algodonite is a rare mineral from the mineral class of " sulfides and sulfosalts " with the chemical formula Cu 1-x As x with x ≈ 0.15 and is therefore chemically a copper arsenide related to sulfides .
Algodonite crystallizes in the hexagonal crystal system , but has only been able to exist in the form of massive, coarse mineral aggregates and crusty coatings of steel-gray to silver-white color. On polished surfaces the mineral shows a strong creamy white color. Fresh algodonite samples have a strong metallic luster . In the air, however, the mineral turns matt gray over time.
Etymology and history
Algodonite was first discovered in 1857 in the Los Algodones mine near Los Algodones in the Chilean province of Elqui and described by F. Field, who named the mineral after its type of locality .
classification
In the Strunz system , algodonite is one of the alloys and alloy-like compounds, a subgroup of sulfides and sulfosalts. After the 8th edition, it forms a group together with Cuprostibit , Domeykit , Koutekit , Kutinait and Novákit . In the 9th edition it forms a separate subgroup of the compounds of semi-metals with copper, silver and gold .
In the Dana system , it forms its own subgroup of sulfides - including selenides and tellurides - with the composition A m B n X p , with a ratio of (m + n) to p of> 3: 1.
Crystal structure
Algodonite crystallizes hexagonally in the space group P 6 3 / mmc (space group no. 194) with the lattice parameters a = 2.588 Å and c = 4.226 Å as well as two formula units per unit cell .
Modifications and varieties
With argentoalgodonite, algodonite forms a variety that contains not only copper but also silver . The chemical formula of argentoalgodonite is (Cu, Ag) 6 As.
Another variety assigned to the algodonite is the whitneyite , a mixture of algodonite and arsenic, solid copper.
As Mohawkit a mineral mixture of algodonite, Domeykit and arsenic-rich copper is referred to.
Education and Locations
Algodonite forms in hydrothermal deposits together with other copper arsenides such as domeykite and koutekite, among others . In addition, solid copper and silver can also occur as additional accompanying minerals .
In addition to the type locality, it was found in Chile, in the United States (US states Colorado and Michigan ), various European countries ( Germany , Switzerland , Austria , Great Britain , Sweden , France , Czech Republic ), in Namibia , New Zealand , Bolivia , Argentina and in Iran .
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. 414 (first edition: 1891).
- Helmut Schrätze , Karl-Ludwig Weiner : Mineralogy. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp. 113 .
- Richard V. Gaines, H. Catherine W. Skinner, Eugene E. Foord, Brian Mason , Abraham Rosenzweig: Dana's New Mineralogy . 8th edition. John Wiley & Sons, New York (et al.) 1997, ISBN 0-471-19310-0 , pp. 37 .
Web links
- Mineral Atlas: Algodonite (wiki)
- Mindat - Algondonite (English)
- American-Mineralogist-Crystal-Structure-Database - Algondonite (English)
- IMA / CNMNC List of Mineral Names - September 2017 (PDF 1.67 MB; Algodonite p. 6)
Individual evidence
- ↑ a b Peter Bayliss: Revised unit-cell dimensions, space group, and chemical formula of some metallic minerals . In: The Canadian Mineralogist . tape 28 , no. 4 , 1990, pp. 741–755 ( rruff.info [PDF; 436 kB ; accessed on October 30, 2017]).
- ^ 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. 57 .
- ↑ Webmineral - Algodonite (English)
- ↑ a b RD Heyding, GJG Despault: The copper / arsenic system and the copper arsenide minerals . In: Canadian Journal of Chemistry . tape 38 , no. 12 , 1960, pp. 2477–2481 , doi : 10.1139 / v60-335 ( nrcresearchpress.com [PDF; accessed October 30, 2017]).
- ↑ a b c Algodonites . 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; 60 kB ; accessed on October 30, 2017]).
- ^ Helmut Schrätze , Karl-Ludwig Weiner : Mineralogie. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp. 113 .
- ↑ F. Field: On Algodonite, a New Mineral containing Arsenic and Copper . In: The Quarterly Journal of the Chemical Society . tape 10 , 1857, pp. 289–292 ( rruff.info [PDF; 153 kB ]).
- ↑ Mindat - Argentoalgondonite (English)
- ↑ Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties . 6th completely revised and supplemented edition. Weise, Munich 2014, ISBN 978-3-921656-80-8 .