Tangeit
| Tangeit | |
|---|---|
 |
|
| General and classification | |
| other names |
Calciovolborthite |
| chemical formula | CaCu [OH | VO 4 ] |
|
Mineral class (and possibly department) |
Phosphates, arsenates and vanadates |
|
System no. to Strunz and to Dana |
8.BH.35 ( 8th edition : VII / B.26) 41.05.01.06 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-disphenoidic; 222 |
| Space group | P 2 1 2 1 2 1 (No. 19) |
| Lattice parameters | a = 7.43 Å ; b = 9.35 Å; c = 5.84 Å |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | 3.5 |
| Density (g / cm 3 ) | measured: 3.75; calculated: [3.84] |
| Cleavage | perfect after {010}, good after {001} |
| Break ; Tenacity | brittle |
| colour | light green to dark green, olive green, yellowish green, gray |
| Line color | light yellowish green |
| transparency | transparent |
| shine | Glass luster, pearlescent on cleavage surfaces |
| Crystal optics | |
| Refractive indices |
n α = 2.010 n β = 2.050 n γ = 2.090 |
| Birefringence | δ = 0.080 |
| Optical character | biaxial negative |
| Axis angle | 2V = 83 ° (measured), 88 ° (calculated) |
Tangeit is a rarely occurring mineral from the mineral class of "phosphates, arsenates and vanadates". It crystallizes in the orthorhombic crystal system with the chemical composition CaCu [OH | VO 4 ] and is therefore chemically a calcium - copper - vanadate with additional hydroxide ions . Many Tangeit mineral samples also contain small amounts of adsorbed water.
Tangeit develops scaly, short prismatic or leafy to thin tabular crystals with a length of up to three millimeters and acute-angled ends, which are often arranged in rosette-shaped mineral aggregates . It can also be found in the form of grape to spherical, fibrous or massive aggregates and crusty coatings. The transparent crystals are light to dark green, yellowish green or gray in color and have a glass-like sheen on the surface .
With Konichalcite , Tangeit forms a seamless series of mixed crystals .
Etymology and history
Was first discovered in the so-called Tangeite Glavnaya vein (Russian главная жила glawnaja Schila ), a copper-vanadium uranium - deposit at Tyuya-Muya (Tyuya-Muyun) in Osh Region in Kyrgyzstan and described in 1925 by Alexander Fersman , of the Mineral named after its first site ( type locality ) in the Tang Gorge within the Ferghana Valley .
The type material of the mineral is kept in the Mineralogical Museum "Alexander Fersman" at the Russian Academy of Sciences in Moscow (Catalog No. m6065 , m6066 and m6068 ).
The term calciovolborthite is sometimes used as a synonym for tangite , but the exact identity of the composition of the material originally named Kalkvolborthite by Heinrich Credner in 1848 and discovered in Friedrichroda in Thuringia together with volborthite is doubtful. Since the calciovolborthite could be tangite as well as vésigniéite , the mineral name was finally discredited in 2006 by the CNMNC along with many others.
classification
Already in the outdated, but partly still in use 8th edition of the mineral classification according to Strunz , Tangeit belonged to the department of "Anhydrous phosphates with foreign anions F, Cl, O, OH", where it was used together with Adelite , Austinite , Duftite , Gabrielsonite , Gottlobite , Cobaltaustinit , Konichalcit and Nickelaustinit the "Adelit-Gruppe" with the system no. VII / B.26 .
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns Tangeit to the department of “Phosphates etc. with additional anions; without H 2 O “. However, this is further subdivided according to the relative size of the cations involved and the molar ratio of the additional anions (OH, etc.) to the phosphate, arsenate or vanadate complex (RO 4 ), so that the mineral can be classified in the sub-section “With medium-sized and mostly large cations; (OH etc.): RO 4 = 1: 1 “can be found, where together with Adelite, Arsendescloizit , Austinite, Cobaltaustinite, Duftite, Gabrielsonite, Gottlobit, Konichalcite and Nickelaustinite the“ Adelite group ”with the system no. 8.BH.35 forms.
Also in the systematics of minerals according to Dana , which is mainly used in the English-speaking area , Tangeit is in the “anhydrous phosphates etc., with hydroxyl or halogen” in the “Adelite group” with the system no. 41.05.01 to be found within the subsection of " Anhydrous phosphates etc., with hydroxyl or halogen with (AB) 2 (XO 4 ) Z q ".
Crystal structure
Tangeit crystallizes orthorhombically in the space group P 2 1 2 1 2 1 (space group no. 19) with the lattice parameters a = 7.43 Å ; b = 9.35 Å; c = 5.84 Å and 4 formula units per unit cell .
Education and Locations
Tangeite forms as a secondary mineral in sandstone and in the oxidation zone of deposits containing vanadium . As accompanying minerals may include barite , calcite , chalcopyrite , chalcocite , chrysocolla , solid copper , malachite , Neotokit , pyrite , Pyrobelonit , quartz , Rhodonit and Tyuyamunit and the limonite limonite occur.
As a rare mineral formation, Tangeit could only be proven at a few sites, whereby so far (as of 2015) around 50 sites are known. In addition to its type locality, the Glavnaya vein, and the nearby Zelenaya cave at Tyuya-Muya (Tyuya-Muyun), the mineral occurred in Kyrgyzstan on Mount Kara-Chagyr about 38 km southeast of Fargʻona ( Fergana ) and thus in the Kyrgyz part of the Ferghanatal revealed.
In Germany Tangeit was able to work in the “Floßberg” mine near Bad Lauterberg in the Harz Mountains in Lower Saxony; at the Nickenicher Weinberg (Sattelberg), in the “Kahlenberg” open-cast mine ( Auf'm Kopp ) near Oberstadtfeld and in the “Caspar” quarry on Ettringer Bellerberg in the Rhineland-Palatinate Volcanic Eifel ; can be found on the southwest coast of the island of Heligoland in Schleswig-Holstein and in the "Glückstern" mine on Berg Gottlob near Friedrichroda in Thuringia.
In Austria, the mineral has so far only been found in the limestone quarries “Dullinger” (No. 21) and “Lienbach” (No. 22b) in the Salzburg municipality of Adnet .
Other locations are in Australia, Chile, Italy, Canada, Mexico, Namibia, Russia, the United Kingdom (UK) and the United States of America (USA).
See also
literature
- K. Nenadkewitch, P. Volkov: La tanguéite - nouvell espèce minérale des mines de Tjuja Moujoun en Ferghana. In: Comptes Rendus (Doklady) de l'Académie des Sciences de l'URSS. 1926, pp. 43–46 ( rruff.info PDF; 188.9 kB, Russian)
Web links
- Mineral Atlas: Tangeit (Wiki)
- Webmineral - Tangeite.
- Database-of-Raman-spectroscopy - Tangeite.
- American-Mineralogist-Crystal-Structure-Database - Tangeite.
Individual evidence
- ↑ Hans Jürgen Rösler : Textbook of Mineralogy . 4th revised and expanded edition. German publishing house for basic industry (VEB), Leipzig 1987, ISBN 3-342-00288-3 , p. 645 .
- ↑ 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. 458 .
- ↑ a b c d Tangeite. 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; 64.4 kB).
- ↑ a b c d e f Mindat - Tangeite.
- ^ Friedrich Klockmann : Klockmanns textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 632 (first edition: 1891).
- ↑ Credner: About the occurrence of vanadic acid copper and manganese copper near Friedrichsrode in the Thuringian Forest. In: Annals of Physics. Volume 150, 1848. - Pogg. Ann. 74, Halle / Leipzig, pp. 546–558 limited preview in the Google book search
- ↑ Ernst AJ Burke: A mass discreditation of GQN Minerals. In: The Canadian Mineralogist. Volume 44, 2006, pp. 1557–1560 ( cnmnc.main.jp PDF; 116 kB, p. 2)
- ↑ Mindat - Number of localities for Tangeit.
- ↑ List of localities for Tangeit in the Mineralienatlas and Mindat