Millerite

Millerite (hair gravel, gravel Nickel, Yellow Nickel gravel, hair pyrite, Trichopyrit, electroless nickel (II ) sulfide ) is a rarely occurring mineral from the mineral class of sulfides and sulfosalts. It crystallizes in the trigonal crystal system with the chemical composition NiS and usually develops thin, elongated crystals with up to eight inches in length brass yellow to bronze color. These are usually collectively referred to as hair -like tufts.

Etymology and history

( Jáchymov ) was Millerit the first time in 1845 by Wilhelm Ritter von Haidinger in the type locality Jáchymov found in the Czech part of the Erzgebirge. It was named after the British mineralogist William Hallowes Miller, who examined the mineral first.

Classification

In the classification by Strunz Millerite is classified in the sulfides and sulfosalts. It is counted among the sulfides with a ratio of metal to sulfur, selenium or tellurium of 1:1. In the eighth edition, it made with Lapieit, Mäkinenit, Mückeit and Zlatogorit a group. In the ninth edition, the alloys are further subdivided according to cations, there is Millerit to find with Mäkinenit in the class of metal sulfides with iron, cobalt or nickel.

In the classification of minerals according to Dana it forms with Mäkinenit a subset of the sulfides - tellurides and selenides, including - with the composition AmBn Xp, with (m n): p = 1:1.

Education and Locations

Millerite usually formed under low temperatures in limestone or barite. Also known as weathering product of other minerals or nickel in sediments can Millerit be formed. It is associated with Gersdorffite, Polydymit, Nickeline, galena, sphalerite, pyrite, chalcopyrite, pyrrhotite, pentlandite, cubanite, calcite, dolomite, siderite, barite and ankerite.

There are known a number of sites ( 695 with as of August 2009) for Millerite. Among the localities include Müsen, knowledge, Ramsbeck, Lünen - Brambauer and Kamsdorf in Germany, Kotalahti in Finland, Kladno in the Czech Republic, Merthyr Tudful in Wales, Kambalda and Leinster in Australia, Bindura in Zimbabwe, Mabilikwe Hill in South Africa, Temagami, Thompson, Brompton Lake and Malartic in Canada, as well as Antwerp, Keokuk, St. Louis and ester Brook Park in the United States.

Crystal structure

Millerite crystallizes in the trigonal crystal system in the space group R3m with lattice parameters a = 9.6071 Å and c = 3.1434 Å, and nine formula units per unit cell. The structure corresponds to the Nickelarsenid structure.

Use

Millerite is a nickel ore and is used as a raw material for the production of elemental nickel.