Volborthite
- Usbekit
- Vanadium Acid copper
Volborthit (also Usbekit ) is a rarely occurring mineral from the mineral class of " phosphates, arsenates and vanadates ." It crystallizes in the monoclinic crystal system with the composition Cu3 [( OH) 2 | V2O7 ] · 2H2O and is therefore chemically seen a hydrous copper vanadate.
Volborthit developed predominantly scaly, fibrous or spongy crusts and rosette-shaped mineral aggregates of greenish- white, yellow -green to olive-green or black-brown color.
Etymology and history
Was first found in Volborthit " copper mine Sofronovskii " in Perm in the Russian Ural region and described in 1838 by Germain Henri Hess, who named the mineral after Alexander Volborth ( 1800-1876 ), a Russian paleontologist who mentioned the mineral for the first time.
Classification
In the now outdated but still in use classification of minerals according to Strunz ( 8th edition ) of the Volborthit belonged to the department of " water -containing phosphates with foreign anions ", where he led the unnamed group formed as a single member VII/D.58.
The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used assigns the Volborthit in the newly defined division of " polyphosphates, Polyarsenate, polyvanadates " one. However, this is further subdivided according to the possible presence of additional anions and crystal water as well as the crystal structure, so that the mineral is found in accordance with the subdivision " diphosphates, etc. with OH and H2O", where it is the only member of the unnamed group 8.FD .05 forms.
The mostly commonly used in English-speaking classification of minerals according to Dana assigns the Volborthit likewise in the class of " phosphates, arsenates and vanadates ", There, however, in the department of " water -containing phosphates, etc. ". Here he is with Martyit in the unnamed group 40.03.10 within the subdivision " water -containing phosphates, etc., with (A2 ) 3 ( XO4 ) 2 × x (H2O) " to find.
Education and Locations
Volborthit forms as a rare secondary mineral in the oxidation zone of vanadium deposits. Accompanying minerals occur among others Atacamit, barite, Brochantite, chrysocolla, gypsum, malachite and Tangeite.
As a rather rare mineral formation Volborthit can indeed be abundant in part to different sites, overall it is not very common. About 120 localities are so far (as of 2012) to be known.
Apart from its type locality, the " copper mine Sofronovskii " stepped Volborthit in Russia nor in the copper mine " Woskressensk " in Perm, in the pit "Alexandrov " at Motovilikha in the Perm region and Potekhina near Sorsk in the Republic of Khakassia on.
In Germany, the mineral found in the Clara mine in Oberwolfach in Baden- Württemberg, at several discovery locations in Bad Lauterberg ( Lower Saxony), in many places in the Eifel as, among others, Andernach and down in Rhineland -Palatinate and in Ronneburg, Garnsdorf and on Gottlob ( pit lucky star ) to Friedrichroda in Thuringia.
In Austria Volborthit has so far been discovered in Notsch in the Gail Valley in Carinthia and in a slag deposits near Kolm - Saigurn in the area of Alteck and High Sonnblick in Salzburg only in diabase quarry.
Other localities lie among others in Argentina, Australia, Chile, the Democratic Republic of the Congo, Greece, Italy, Japan, Kazakhstan, Kyrgyzstan, Namibia, Poland, Portugal, Slovakia, Spain, Czech Republic, Hungary, Uzbekistan, the United Kingdom and the United States of America.
Crystal structure
Volborthit crystallizes in the monoclinic space group C2 / m ( Raumgruppen-Nr. 12) with the lattice parameters a = 10.61 Å; b = 5.87 Å; c = 7.21 Å and 95.0 ° β = and two formula units per unit cell.