Leisingite
| Leisingite | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA 1995-011 |
| chemical formula | (Cu 2+ , Mg, Zn) 2 (Mg, Fe) Te 6+ O 6 · 6H 2 O |
|
Mineral class (and possibly department) |
Oxides and hydroxides |
|
System no. to Strunz and to Dana |
4.FL. 65 02.33.09.01 |
| Crystallographic Data | |
| Crystal system | trigonal |
| Crystal class ; symbol | ditrigonal-scalenohedral; 3 2 / m |
| Space group | P 3 1 m (No. 162) |
| Lattice parameters | a = 5.32 Å ; c = 9.72 Å |
| Formula units | Z = 1 |
| Frequent crystal faces | {0001}, {000 1 }, {10 1 0}, {11 2 0} |
| Physical Properties | |
| Mohs hardness | 3 to 4 |
| Density (g / cm 3 ) | calculated: 3.41 |
| Cleavage | completely after {001} |
| Break ; Tenacity | uneven; brittle |
| colour | light yellow to yellow-orange |
| Line color | light yellow |
| transparency | transparent to translucent |
| shine | Glass gloss |
| Crystal optics | |
| Refractive indices |
n ω = 1.803 n ε = 1.581 |
| Birefringence | δ = 0.222 |
| Optical character | uniaxial negative |
Leisingite is a very seldom occurring mineral from the mineral class of " oxides and hydroxides " with the idealized chemical composition CuMg 2 Te 6+ O 6 · 6H 2 O and therefore chemically a water-containing copper - magnesium - tellurium oxide.
Leisingite crystallizes in the trigonal crystal system and develops mostly hexagonal, tabular crystals with a glass-like sheen on the surfaces, which can stand individually or be grouped in tufted and rosette-like aggregates . The transparent to translucent crystals are light yellow to orange-yellow in color and the color of the streak is light yellow.
Etymology and history
Leisingite was discovered in the "Centennial Eureka Mine" in the Tintic Mountains ( Juab County ) in the US state of Utah and described in 1996 by Andrew C. Roberts, Lee A. Groat, Joel D. Grice, Robert A. Gault, Martin C. Jensen, Elizabeth A. Moffatt and John AR Stirling, who named the mineral after Joseph F. Leising (1949–) in recognition of his assistance in collecting secondary minerals from the spoil heaps of the Centennial Eureka Mine.
classification
Since leisingite was only recognized as an independent mineral in 1995, it is not yet included in the 8th edition of the Strunz mineral classification, which has been outdated since 1977 . Only in the Lapis mineral directory according to Stefan Weiß, which, out of consideration for private collectors and institutional collections, is still based on this classic classification by Karl Hugo Strunz , the mineral received the system and mineral number. IV / K.15-18 . In the "Lapis Classification", this corresponds to the class of "oxides and hydroxides" and then the department "sulfites, Selenite and tellurites" where Leisingit with Agait , Andychristyit , backit , Bairdit , Brumadoit , Cesbronit , Cuzticit , Dagenaisit , Eckhardit , Frankhawthorneit , Fuettererit , Jensenit , Khinit , Kuranakhit , Markcooperit , Mcalpineit , Mojaveit , Montanit , Ottoit , Paratimroseit , Raisait , Timroseit , Utahit , xocolatlite , Xocomecatlit and Yafsoanit the group of "tellurates with [Te 6+ O 6 ] 6- - Groups and related structures ”.
The 9th edition of Strunz's mineral systematics, valid since 2001 and updated by the International Mineralogical Association (IMA) until 2009, also assigns leisingite to the class of "oxides and hydroxides", but in the category of "hydroxides (without V or U) " a. This is further subdivided according to the possible presence of crystal water and the crystal structure, so that the mineral is classified according to its composition and structure in the subdivision of “hydroxides with H 2 O ± (OH); Layers of edge-linked octahedra “can be found, where it is the only member of the unnamed group 4.FL.65 .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns leisingite to the class of " sulfates , chromates and molybdates " and there to the category of " selenates and tellurates ". Here he is the only member of the unnamed group February 33, 2009 within the subdivision of “ Selenates and Tellurates with A + (B 2+ ) m XO 6 Z q × x (H 2 O), x can be equal to 0”.
Crystal structure
Leisingite crystallizes trigonally in the space group P 3 1 m (space group no. 162) with the lattice parameters a = 5.32 Å and c = 9.72 Å and one formula unit per unit cell .
Education and Locations
Leisingite is a very rare secondary mineral that forms in the oxidation zone of tellurium-containing copper-gold-silver deposits . Accompanying minerals include cesbronite , jensenite , hematite and quartz .
Apart from its type locality "Centennial Eureka Mine", leisingite could not be detected at any other location so far (status: 2011).
See also
literature
- Andrew C. Roberts, Lee A. Groat, Joel D. Grice, Robert A. Gault, Martin C. Jensen, Elizabeth A. Moffatt, John AR Stirling: Leisingite, Cu (Mg, Cu, Fe, Zn) 2 Te 6+ 0 6 · 6H 2 0, a new mineral species from the Centennial Eureka mine, Juab County, Utah . In: Mineralogical Magazine . tape 60 , 1996, pp. 653–657 (English, rruff.info [PDF; 332 kB ; accessed on October 7, 2019]).
Web links
- Mineral Atlas: Leisingite (Wiki)
- American-Mineralogist-Crystal-Structure-Database - Leisingite. In: rruff.geo.arizona.edu. Retrieved October 7, 2019 .
Individual evidence
- ↑ a b Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: September 2019. (PDF 2672 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, September 2019, accessed October 7, 2019 .
- ↑ a b c d 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. 246 .
- ↑ Sean M. Margison, Joel D. Grice, Lee A. Groat: The crystal structure of Leisingite, (Cu 2+ , Mg, Zn) 2 (Mg, Fe) Te 6+ O 6 · 6H 2 O . In: The American Mineralogist . tape 35 , 1997, pp. 759–763 (English, rruff.geo.arizona.edu [PDF; 440 kB ; accessed on October 7, 2019]).
- ^ David Barthelmy: Leisingite Mineral Data. In: webmineral.com. Retrieved October 7, 2019 .
- ↑ a b Leisingite . 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; 67 kB ; accessed on October 7, 2019]).
- ↑ a b c d Leisingite. In: mindat.org. Hudson Institute of Mineralogy, accessed October 7, 2019 .
- ↑ 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 .
- ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed October 7, 2019 .