Cadmoselite

Cadmoselit is a very rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the hexagonal crystal system with the composition of CdSe, cadmium selenide is therefore seen chemically.

Cadmoselit developed only very small, hexagonal pyramidal crystals in the range of some tenths of a millimeter with horizontal striping. The color of the mineral is unusually variable. With indirect lighting it looks black in reflected light, however, is light gray. Add oil dipped the color appears slightly brown with inner brownish reflections.

Etymology and history

Was first found in 1957 in the Cadmoselit " Ust'Uyok " deposit at Turan ( South Siberia, Russia) and described by EZ Buryanova, GA and AI Kovalev Komkov who named the mineral after its composition, cadmium and selenium.

Classification

In the old ( 8th edition ) and new classification of minerals according to Strunz ( 9th edition ) of the Cadmoselit belongs to the department of " sulfides and sulfosalts with the molar ratio of metal: sulfur, selenium, tellurium = 1: 1". The 9th edition of Strunz'schen Mineral classification divided here but now more specific to the nature of the cations involved and the mineral is therefore in accordance with the subdivision " with zinc (Zn ), iron ( Fe ), copper (Cu ), silver ( Ag), etc. ", where it forms a separate group together with Hypercinnabarit, Greenockit, Rambergit and wurtzite.

The commonly used in English-speaking classification of minerals according to Dana assigns the Cadmoselit the subdivision of " sulfides including selenides and tellurides with the general composition AmBnXp and the molar ratio (m n): p = 1:1". There he finds himself together with Greenockit, Rambergit and wurtzite in the Wurtzitgruppe ( Hexagonal: P63mc ).

Education and Locations

Cadmoselit forms in sedimentary layers under reducing conditions at medium to high alkalinity. Accompanying minerals include calcite, Clausthalite, Ferroselit, Greenockit, laumontite, pyrite and native selenium.

Except at its type locality " Ust'Uyok " in Russia Cadmoselit has so far only in the " Kidd Creek Mine " in the district of Cochrane ( Ontario) in Canada and in the " Tumiñico mine ," Sierra de Cacho in the Argentine province of La Rioja (as 2009).

Crystal structure

Cadmoselit crystallized hexagonal space group P63mc with the lattice parameters a = 4.30 Å and c = 7.02 Å and two formula units per unit cell.