Vauxite

Vauxit is a very rarely occurring mineral from the mineral class of " phosphates, arsenates and vanadates ." It crystallizes in the triclinic crystal system with the chemical composition Fe2 Al2 [ OH | PO4 ] 2 • 6H 2 O and usually develops larger partial radial- mineral aggregates consisting of many tabular to prismatic single crystals of sky-blue to blue- green color.

Etymology and history

Was named the mineral after George Vaux, Jr. (1863-1927), an American lawyer and mineral collectors.

For the first time it was found in 1922 in the " Siglo Veinte Mine ( Llallagua Mine) " in Llallagua in Bolivia and described by Samuel George Gordon ( 1897-1953 ), who described it as another new mineral of the archaeological site and the Metavauxit and paravauxite ..

Classification

In the old ( 8th edition ) and new classification of minerals ( 9th Edition ) by Strunz heard the Vauxit to the Department of " water -containing phosphates with foreign anions ." Since the new Strunz'schen Mineral classification, this department is, however, precisely also on the size of the cations and the ratio of hydroxyl group divided into cation complex and the mineral now in the subsection "With only medium-sized cations, (OH, etc.): RO 4 = 1:1 and < 2:1 to find. "

The commonly used in English-speaking classification of minerals according to Dana assigns the Vauxit in the department of " hydrated phosphates, etc., with hydroxyl or halogen with (AB ) 4 ( XO4 ) 3Zq • x (H2O) " where he along with paravauxite, Sigloit, Gordonit, Mangangordonit and Kastningit the unnamed group " 42.11.14 " forms.

Education and Locations

Vauxit is a secondary mineral that is formed by the weathering of apatite. Accompanying minerals include Wavellite, paravauxite and marcasite.

So far the only mineral in Bolivia, are firstly detected at its type locality " Siglo Veinte Mine ( Llallagua Mine) " in Llallagua in Potosí and on the other at Huanuni in Oruro.

Crystal structure

Vauxit crystallized in the triclinic space group with lattice parameters a = 9.13 Å; b = 11.59 Å; c = 6.14 Å; α = 98.3 °; β = 92.0 ° and γ = 108.4 ° and two formula units per unit cell.