Grunerite

The mineral grunerite, also Grünerit, amosite, or brown asbestos called, is a rarely occurring chain silicate from the group of amphiboles. It crystallizes in the monoclinic crystal system with the chemical composition ( Fe2 , Mg) 7 [ OH | Si4O11 ] 2 and developed mostly acicular to fibrous, radial- crystals and aggregates of ash or brownish green to brown in color. The crystals can be translucent and show on their faces vitreous luster, with opaque, fibrous habit, the surface shows shimmering pearlescent.

Etymology and history

Was first discovered in 1853 at Grunerite " Ravine de Sarvengude " at Collobrières in France and described by Gustav Adolf Kenngott that. Mineral in honor of the Swiss- French chemist Louis Emmanuel Gruner named after this that the first analyzed

Classification

In the old ( 8th edition ) and new classification of minerals ( 9th Edition ) by Strunz found the grunerite in the Department of chain and chain silicates ( inosilicates ). The old system shares this department to not continue and summarizes only the members of the amphibole group together, with the Grunerite no special amphibole is allocated. The new system, however, divided the chains and chain silicates further and grunerite the new sub-division of " Klinoamphibole " to.

In the scheme of minerals by Dana of grunerite also heard though to the Department of chain and chain silicates, there but due to its crystal structure to the subdivision of the chain silicates with double, unbranched chains (W = 2) and there to Group 1 of the monoclinic Mg -Fe- Mn -Li amphiboles.

Modifications and varieties

Fine fibrous, asbestiform varieties of Grunerits are referred to as amosite.

Education and Locations

Grunerite formed by contact metamorphism in the medium to high-grade iron - formations and some blueschists. Accompanying minerals include fayalite, garnets, hematite, hedenbergite, magnetite, quartz, and riebeckite.

Worldwide, grunerite so far (as of 2010) are detected at around 150 localities, as in Australia, Bolivia, Brazil, China, Finland, France, India, Japan, Cameroon, Canada, Madagascar, Norway, Austria, Portugal, Russia, Sweden, Slovakia, Spain, South Africa, Czech Republic, Ukraine, Hungary, the United Kingdom ( UK ) and the United States (USA).

Amosite is mined mainly in South Africa in the Asbestos Mines of South Africa. The term is a portmanteau of the initials of the South African mining company AMOS

Crystal structure

Grunerite crystallizes in the monoclinic space group C2 / m with lattice parameters a = 9.564 Å; b = 18.393 Å; c = 5.339 Å and β = 101.892 °, and two formula units per unit cell.

Use

Amosite may no longer be used as an asbestos -like material in Europe today. In other countries but it is still used to some extent as a building material.

Precautions

Prolonged exposure to risk serious damage to health is through inhalation. The substance may cause cancer.