Anthophyllite

• Antophyllite

The mineral anthophyllite (formerly antophyllite ) is a common chain silicate from the group of orthorhombic amphiboles. It crystallizes in the orthorhombic crystal system with the chemical composition of (Mg, Fe2 ) 7 [ OH | Si4O11 ] 2, and usually develops granular and fibrous radiating aggregates, but also long prismatic crystals of different colors, wherein brown however predominant. Other colors such as yellow, gray, white, green are mixed in, but occurs also for themselves. The crystals show vitreous luster, cleavage surfaces contrast pearly. In weathering anthophyllite is matt.

Etymology and history

Was because of its name derives dark brown color the fruits of the clove, also called mother Elke, whose Latin name is Anthophylli, this name derives in turn from the Greek ἄνθος anthos for " flower " and φύλλον phyllon for "Leaf " her.

Anthophyllite was first described in 1801 by Christian Friedrich Schumacher. As a type locality applies Kjennerudvann at Kongsberg in Norway.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the anthophyllite still belonged to the general ward of the " chain silicates and phyllosilicates ( inosilicates ) ", where he, together with ferro - anthophyllite, Ferrogedrit, Ferroholmquistit, gedrite, Holmquistit, Natriumanthophyllit sodium - ferro - anthophyllite, sodium Ferrogedrit, Natriumgedrit, Protoanthophyllit, proto - anthophyllite Ferro, Ferro - anthophyllite - Protomangano the subgroup of " orthorhombic amphiboles " with the system no. VIII/F.12 formed within the amphibole group.

The 9th edition valid since 2001 and also by the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification leads to anthophyllite also under the Department of " chains and chain silicates ( inosilicates ), but this is now precisely divided according to the type of chain formation and the mineral is in accordance with the division of the " chains and chain silicates with 2- periodic double chains, Si4O11; Amphibole family, Orthoamphibole ", where he was named the ". Anthophyllitgruppe "with the system no 9.DD.05 and forms the other members of ferro - anthophyllite, Ferrogedrit, Ferroholmquistit, gedrite, Holmquistit, Natriumanthophyllit, sodium - ferro - anthophyllite, sodium Ferrogedrit, Natriumgedrit, Protoanthophyllit, Proto Ferro - anthophyllite Ferro - anthophyllite and Protomangano.

The commonly used in English-speaking classification of minerals according to Dana assigns the anthophyllite in the department of " chain silicates with double, unbranched chains, W = 2". Here he is with Magnesiumastrophyllit, Protoanthophyllit, ferro - anthophyllite, Proto ferro - anthophyllite, Protomangano - ferro - anthophyllite, Natriumanthophyllit, sodium - ferro - anthophyllite, magnesio - gedrite, gedrite, Ferrogedrit, sodium Ferrogedrit, Natriumgedrit, magnesio - Holmquistit, Holmquistit and Ferroholmquistit in the unnamed group 66.01.02.02 within the sub-division of " chain silicates: Double unbranched chains, W = 2 amphibole configuration " to find.

Modifications and varieties

As Herman ball over an egg-shaped aggregate of phlogopite and anthophyllite core - crust of Heřmanov in the Czech Republic is called.

Education and Locations

Anthophyllite formed by contact or regional metamorphism in gneisses, pegmatites, and serpentinites. Accompanying minerals include cordierite, talc, chlorite, sillimanite, various mica, olivine, hornblende and gedrite, cummingtonite - Magnesio, grenades, staurolite and plagioclase.

Could Worldwide anthophyllite so far (as of 2010) are detected at 475 localities, so among other things in Egypt, Antarctica, in Ethiopia, Australia, Bolivia, Brazil, Burkina Faso, China, Germany, Finland, France, Greenland, India, Indonesia, Italy, Japan, Canada, Colombia, New Zealand, Norway, Austria, Poland, Romania, Russia, Sweden, Switzerland, Zimbabwe, Slovakia, Spain, South Africa, Tajikistan, Taiwan, Czech Republic, Ukraine, Hungary, the United Kingdom ( UK) and in the United States of America (USA).

Crystal structure

Anthophyllite crystallized in the orthorhombic space group Pnma ( Raumgruppen-Nr. 62) with the lattice parameters a = 18.56 Å; b = 18.01 Å and c = 5.28 Å and four formula units per unit cell.

Use

Anthophyllite found under the name of amphibole asbestos used in the construction industry (asbestos cement).