Wiserite
| Wiserite | |
|---|---|
 |
|
| General and classification | |
| other names |
Wiserite, Wiserita |
| chemical formula |
|
|
Mineral class (and possibly department) |
Borates (formerly carbonates, nitrates and borates) |
|
System no. to Strunz and to Dana |
6.BA.20 ( 8th edition : V / H.03) 01/27/10/01 |
| Similar minerals | Luneburgite |
| Crystallographic Data | |
| Crystal system | tetragonal |
| Crystal class ; symbol | tetragonal-dipyramidal; 4 / m |
| Space group | P 4 / n (No. 85) |
| Lattice parameters | a = 20.19 Å ; c = 3.28 Å |
| Frequent crystal faces | {100}, {110} |
| Physical Properties | |
| Mohs hardness | 2.5 |
| Density (g / cm 3 ) | measured: 3.54; calculated: 3.57 |
| Cleavage | perfectly |
| colour | white, light pink brown, reddish brown |
| Line color | White |
| transparency | transparent |
| shine | Glass gloss |
| Crystal optics | |
| Refractive indices |
n ω = 1.751 to 1.760 n ε = 1.700 to 1.717 |
| Birefringence | δ = 0.051 |
| Optical character | uniaxial negative |
| Pleochroism | Visible: ω = colorless to bright orange-brown ε = bright to dark orange- brown |
Wiserite is a rarely occurring mineral from the mineral class of " borates " (formerly carbonates, nitrates and borates ) with the chemical composition Mn 14 [Cl | (OH) 8 | (B 2 O 5 ) 4 ] · (Si, Mg) ( O, OH) 4 and, from a chemical point of view, a manganese borate with additional chlorine and hydroxide ions as well as silicon and oxygen ions . Magnesium or hydroxide ions can partially represent the silicon or oxygen ions ( substitution , diadochy), which is indicated by the round brackets at the end of the formula.
Wiserite crystallizes in the tetragonal crystal system and develops fibrous to prismatic crystals up to about one centimeter in size, which are stretched along the c-axis [001]. but it can also occur in the form of tabular, fine-grained and coarse mineral aggregates . The transparent crystals are white, light pink-brown or reddish-brown in color and have a glass-like sheen on the surface . In fibrous aggregate form, silk gloss is also possible.
Etymology and history
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The mineral was first discovered in some mineral samples from the Gonzen iron mine in the Swiss canton of St. Gallen , which the Swiss businessman and geologist David Friedrich Wiser had received in 1841 from the son of the then mine owner Bernhard Neher . He described the new mineral in 1842 under the name "white carbonic acid manganese", but left the description of the geology to Arnold Escher von der Linth due to his better knowledge .
The name Wiserit, which is still valid today, was coined by Wilhelm von Haidinger in 1845 in honor of the person who first described it.
The type material of the mineral is listed at the ETH Zurich in Switzerland under catalog no. 194501 and at Harvard University in Cambridge under catalog no. 126918 and kept at the National Museum of Natural History in Washington, DC, USA.
classification
In the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , the wiserite still belonged to the common mineral class of the "carbonates, nitrates and borates" and there to the department of the "group borates", where together with Lüneburgite it formed the "Wiserit-Lüneburgite- Group "with the system no. V / H.03 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), assigns wiserite to the now independent class of "borates" and there in the department of "diborates". This is further subdivided according to the crystal structure , so that the mineral is classified according to its structure in the subsection “Island diborates (Neso diborates) with double triangles B 2 (O, OH) 5 ; 2 (2Δ); 2 (2Δ) + OH etc. ”can be found where it is the only member of the unnamed group 6.BA.20 .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Wiserite to the common class of "carbonates, nitrates and borates" and there in the department of "borates", like the outdated Strunz system. Here he can be found as the only member of the unnamed group 01/27/10 within the subdivision “ Compound Borates”.
Crystal structure
Wiserite crystallizes tetragonally in the space group P 4 / n (space group no. 85) with the lattice parameters a = 20.19 Å and c = 3.28 Å as well as two formula units per unit cell .
The crystal structure of Wiserit consists of a framework with 2- and 3-membered, corner-sharing bands of edge-sharing Mn (O, OH) 6 - octahedra and tetragonal Mn (O, OH) 5 - pyramids parallel to the c-axis [001]. The framework is stabilized by B 2 O 5 groups and (Si, Mg) tetrahedra ; large channels parallel to [001] take up Cl ions.
Education and Locations
Wiserite forms as an accessory component in stratiform manganese deposits . As accompanying minerals may include Alleghanyite , calcite , Galaxit , Hausmannite , Jakobsit , Pyrobelonit , Pyrochroit , rhodochrosite , Jimboit , Sussexit , Alabandite , Tephroit , Gageit occur.
As a rare mineral formation, Wiserite is only known from a few sites, with around 15 sites being documented so far. In addition to its type locality Gonzen in the Sarganserland, the mineral in the Swiss canton of St. Gallen was also found in the nearby mining area of Naus near Wartau in the Werdenberg district . However, there is said to be another site for Wiserite in Val d'Anniviers in the Swiss canton of Valais.
Other previously known sites are the Kombat Mine in the Oshikoto region of Namibia and a number of manganese ore mines in the Chūbu , Kantō and Kinki regions on the Japanese island of Honshū .
literature
- David Friedrich Wiser: About the minerals occurring in the iron pits at Gonzen near Sargans in the canton of St. Gallen, along with a few comments with mixed contents . In: New yearbook for mineralogy, geognosy, geology and petrefacts customer . Year 1842, 1842, p. 505-527 ( rruff.info [PDF; 761 kB ; accessed on November 5, 2018]).
- Philippe Roth: Minerals first discovered in Switzerland and minerals named after Swiss individuals . 1st edition. Kristallografik Verlag, Achberg 2007, ISBN 3-9807561-8-1 , p. 156-157 .
Web links
- Mineral Atlas: Wiserite (Wiki)
- RRUFF Database-of-Raman-spectroscopy - Wiserite (English)
- American-Mineralogist-Crystal-Structure-Database - Wiserite (English)
Individual evidence
- ^ IMA / CNMNC List of Mineral Names; September 2018 (PDF 1709 kB)
- ↑ a b c d e f 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. 339 .
- ↑ Webmineral - Wiserite (English)
- ↑ a b c d e f g h Wiserite . 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; 68 kB ; accessed on November 5, 2018]).
- ↑ 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 .
- ↑ a b c Mindat - Wiserite (English)
- ↑ David Friedrich Wiser: About the minerals occurring in the iron mines at Gonzen near Sargans in the canton of St. Gallen, along with some mixed-up comments . In: New yearbook for mineralogy, geognosy, geology and petrefacts customer . Year 1842, 1842, p. 505-527 ( rruff.info [PDF; 761 kB ; accessed on November 5, 2018]).
- ^ Wilhelm Haidinger: Handbook of determining mineralogy . Braumüller & Seidel, Vienna 1845, p. 493 ( rruff.info [PDF; 450 kB ; accessed on November 5, 2018] Second class: Geogenide. I. order. Haloids. Wiserite).
- ↑ Catalog of Type Mineral Specimens - W. (PDF 52 kB) In: docs.wixstatic.com. Commission on Museums (IMA), December 12, 2018, accessed August 29, 2019 .
- ↑ Mindat - Number of localities for Wiserite (English)
- ↑ Mineralienatlas : mining area Naus, Wartau, canton St. Gallen (literature sources see there)
- ^ Occurrences and sites in Switzerland - Minerals in Switzerland W
- ↑ Find location list for Wiserite in the Mineralienatlas and in Mindat