Olsacherite
| Olsacherite | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA 1969-009 |
| chemical formula |
|
|
Mineral class (and possibly department) |
Sulfates (including selenates, tellurates, chromates, molybdates, and tungstates) |
|
System no. to Strunz and to Dana |
7.AD.35 ( 8th edition : VI / B.13) 01.32.03.01 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-disphenoidic; 222 |
| Space group | P 22 1 2 (No. 17, position 3) |
| Lattice parameters | a = 8.42 Å ; b = 10.96 Å; c = 7.00 Å |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | 3 to 3.5 |
| Density (g / cm 3 ) | calculated: 6.55 |
| Cleavage | good after {101}, indistinct after {010} |
| Break ; Tenacity | very brittle |
| colour | colorless |
| Line color | White |
| transparency | transparent to translucent |
| shine | Glass gloss, matt in crusts |
| Crystal optics | |
| Refractive indices |
n α = 1.945 n β = 1.966 n γ = 1.983 |
| Birefringence | δ = 0.038 |
| Optical character | biaxial negative |
| Axis angle | 2V = 80 ° (measured), 82 ° (calculated) |
| Other properties | |
| Special features | pyroelectric |
Olsacherite is a very rarely occurring mineral from the mineral class of "sulfates (including selenates, tellurates, chromates, molybdates and tungstates)" with the chemical composition Pb 2 [SO 4 | SeO 4 ] and is therefore chemically a lead - selenate with additional Sulfate ions .
Olsacherite crystallizes in the orthorhombic crystal system and develops sharply contoured, needle-like crystals up to about two millimeters in length, which are stretched along the b-axis. The mineral is usually colorless and transparent with a glass-like sheen on the surfaces. However, due to multiple refraction due to lattice construction defects or polycrystalline formation, olsacherite can also be translucent white.
Etymology and history
Olsacherite was first discovered in the Mina Virgen de Surumi (Pacajake Mine) in Pakajake Canyon about 20 km northeast of Colquechaca in the Bolivian Department of Potosí . The mineral was described in 1969 by Cornelius Searle Hurlbut (1906-2005) and Lorenzo Francisco Aristarain (1926-2013), who named it after the Argentine professor of mineralogy at the University of Cordoba , Juan Augusto Olsacher (1903-1964).
The type material of the mineral is stored at Harvard University in Cambridge (Massachusetts) in the USA (Catalog No. 110966).
classification
Olsacherite is already not listed in the outdated 8th edition of the mineral classification according to Strunz . Only in the most recently revised and updated Lapis mineral directory by Stefan Weiß, which, out of consideration for private collectors and institutional collections, is still based on this classic systematics by Karl Hugo Strunz , was the mineral given the system and mineral number. VI / B.13-20 . In the "lapis system" this corresponds to the class of "sulfates, chromates, molybdates and tungstates" and there the department "anhydrous sulfates, with foreign anions ", where olsacherite together with lanarkite , grandreefit , pseudograndreefit , leadhillite , macphersonite , susannite one forms an independent but unnamed group.
The 9th edition of Strunz's mineral systematics, valid since 2001 and updated by the International Mineralogical Association (IMA) until 2009, also assigns olsacherite to the category of "sulfates (selenates, etc.) without additional anions, without H 2 O". However, this is further subdivided according to the relative size of the cations involved , so that the mineral can be found according to its composition in the subsection "With only large cations", where together with angelsite , barite and celestine, the " barite group" with the system No. 7.AD.35 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the olsacherite to the class of "sulfates (and relatives)" and there in the section "composite sulfates". Here he is to be found as the only member of the unnamed group January 32, 2003 within the sub-section “ Compound sulfates (anhydrous) with simple double anionic formula ”.
Crystal structure
Olsacherite crystallizes orthorhombically in space group P 22 1 2 (space group no. 17, position 3) with the lattice parameters a = 8.42 Å ; b = 1.96 Å and c = 7.0 Å and 4 formula units per unit cell .
Education and Locations
Olsacherit formed secondarily as a conversion product of Penroseite in the oxidation zone of selenium-containing , hydrothermal deposits . Ahlfeldite , chalcomenite , goethite , lepidocrocite and / or penrosite can occur as accompanying minerals depending on where they were found.
Olsacherite is one of the very rare mineral formations, of which only a few samples exist that were collected at fewer than 10 previously known sites (as of 2019). In addition to its type locality Mina Virgen de Surumi in Pakajake Canyon in the province of Chayanta , the mineral was only found in Bolivia on the spoil heaps of the El Dragón mine in the province of Antonio Quijarro .
Other previously known sites are the El Chire prospection near Los Llantenes in the Vinchina department (La Rioja) and the Cacheuta mine at the Cerro de Cacheuta (Sierra de Cacheuta) in the Luján de Cuyo department ( Mendoza province ) in Argentina; the Coldwell Complex in the Thunder Bay District in the Canadian province of Ontario; Liauzun near Olloix in the canton of Saint-Amant-Tallende in the French department of Puy-de-Dôme (Auvergne); the Baccu Locci mine near Villaputzu in the Sarrabus-Gerrei region on the Italian island of Sardinia ; in the northern fumarole field near the Tolbachik volcano on the Kamchatka Peninsula in the Far East of Russia; the Waterbank Mine near the village of Ecton in the English county of Staffordshire and the Santa Rosa Mine near Malpais Mesa in the Inyo Mountains in the county of California (USA).
See also
literature
- CS Hurlbut Jr., LF Aristarain: Olsacherite, Pb 2 (SO 4 ) (SeO 4 ), a new mineral from Bolivia . In: The American Mineralogist . tape 54 , 1969, p. 1519–1527 (English, available online at rruff.info [PDF; 530 kB ; accessed on May 5, 2019]).
Web links
- Mineral Atlas: Olsacherite (Wiki)
- David Barthelmy: Olsacherite Mineral Data. In: webmineral.com. Accessed May 5, 2019 .
- Olsacherite search results. In: rruff.info. Database of Raman spectroscopy, X-ray diffraction and chemistry of minerals (RRUFF), accessed on May 5, 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: March 2019. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, March 2019, accessed May 20, 2019 .
- ↑ 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. 370 (English).
- ↑ a b c d e f Olsacherite . 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 May 5, 2019]).
- ↑ a b c d e Olsacherite. In: mindat.org. Hudson Institute of Mineralogy, accessed May 5, 2019 .
- ↑ Hurlbutite . 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 May 5, 2019]).
- ↑ Kai Carver: Dr Cornelius Searle “Connie” Hurlbut, Jr. In: findagrave.com. Find A Grave, accessed May 5, 2019 .
- ↑ Jorge Eduardo Rusansky, Hebe Dina Gay: Necrológica Dr. Lorenzo Francisco Aristarain (1926-2013). In: scielo.org.ar. Scientific Electronic Library Online, accessed on May 5, 2019 (published in: Revista de la Asociación Geológica Argentina Volume 71, No. 3, Buenos Aires 2014).
- ↑ a b MH Hey: Twenty-sixth list of new mineral names . In: Mineralogical Magazine . tape 37 , no. 292 , December 1970, p. 954–967 (English, available online at rruff.info [PDF; 924 kB ; accessed on May 5, 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 April 25, 2019 .
- ↑ Localities for Olsacherite. In: mindat.org. Hudson Institute of Mineralogy, accessed May 5, 2019 .
- ↑ Find location list for olsacherite at the Mineralienatlas and at Mindat