Anapaite

Anapait (also Tamanit ) is a rarely occurring mineral from the mineral class of hydrous phosphates without foreign anions. It crystallizes in the triclinic crystal system with the chemical composition Ca2Fe2 [ PO4 ] 2 • 4 H2Ound developed either tabular crystals or globular, rosette-shaped and granular aggregates of light to dark green color.

Etymology and history

Anapait was first found in southern Russia in 1902 in an iron ore mine near Anapa and studied by A. Sachs. He named it after its place of discovery Anapait. 1903 by S. P. Popoff a similar mineral described that he called Tamanit. However, it turned out that it is identical minerals in Anapait and Tamanit. The name first used Anapait was retained.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the Anapait belonged to the mineral class of " phosphates, arsenates and vanadates " and then to the Department of " water -containing phosphates without foreign anions ", where he is the only member of the independent group VII / C.19 formed.

The 9th edition used since 2001 and valid by the International Mineralogical Association (IMA ) of the Strunz'schen Mineral classification assigns the Anapait also in the class of " phosphates, arsenates and vanadates " and there in the department of " Phosphates without additional anions, with H2O " one. This division, however, is further divided according to the size of the involved cations and the ratio of phosphate, arsenate or Vanadatkomplexes ( RO 4 ) to the contained water of crystallization, so that the mineral according to its composition in the subsection "With large and medium-sized cations, RO 4: H2O <1: 1 is to find "where it forms the unnamed group 8.CH.10 the only member.

The mainly common in English-speaking classification of minerals according to Dana assigns the Anapait in the class of " phosphates, arsenates and vanadates " and there in the department of " water -containing phosphates, etc. " field. Here he is the only member of the unnamed group 40.02.01 within the sub-division of " water -containing phosphates, etc., with A2 ( B2 ) 2 ( XO4 ) × x (H2O) " to find.

Education and Locations

Anapait is a so-called secondary mineral. It is likely to form in the oxidation zone oolitic iron ores together with siderite and limonite, in the trunks of fossil trees, or in lacustrine sediments.

There are currently (as of December 2010) 22 localities known. These include, in addition to the type locality Anapa in Russia, among other Messel, Ehrenfriedersdorf and Sondheim in Germany, San Giovanni Valdarno and Cavriglia in Italy, Malawi, Cromwell in New Zealand, Lleida in Spain, Crimea in Ukraine and Corcoran, Lyon County and Groton / New Hampshire in the United States.

Crystal structure

Anapait crystallizes in a trikinen crystal structure with space group P1 with the lattice constants a = 6.447 angstrom, b = 6.816 Å, c = 5.898 Å, α = 101.64 °, β = 104.24 ° and γ = 70.76 ° and a formula unit per unit cell.