Laurionite

Laurionite is a mineral from the mineral class of halides. It crystallizes in the orthorhombic crystal system with the chemical composition of Pb ( OH) Cl and developed only colorless or white, to thin tabular prismatic crystals of most conspicuous form angles up to one centimeter in length.

Etymology and history

Was first found in 1887 Laurionite at various slag sites in the area around Laurion in the Greek region of Attica and described by Rudolph Ignatz Koechlin ( 1862-1939 ), who named the mineral after its type locality.

Classification

In the old ( 8th edition ) and new classification of minerals according to Strunz ( 9th edition ) of the Laurionite belongs to the Department of oxyhalides (and related double halides ). The new Strunz'sche Mineral classification divided here but now more precisely following the cations involved in the formula and the mineral is in accordance with the subsection " Using Pb (As, Sb, Bi) without Cu ".

The classification of minerals according to Dana assigns the Laurionite also the Oxihalogeniden to there, however, according to the classification by chemical composition in the subdivision " oxyhalides and hydroxyhalides having the formula A (O, OH) Xq ".

Education and Locations

Laurionite one hand forms in ancient, containing lead, caused by metalworking slag under the influence of salt water, on the other hand but also as a secondary mineral in the oxidation zone of lead-containing mineral deposits. Accompanying minerals include anglesite, cerussite, Fiedlerit, Paralaurionit, Penfieldit and Phosgenite.

Still be detected, in addition to its type locality Laurion in Greece in some areas of Australia, Germany, France, Great Britain, Italy, Canada, Austria, South Africa, Czech Republic, Tunisia and the: So far, the mineral could worldwide to almost 40 sites (2009 version) USA.

Crystal structure

Laurionite crystallizes in the space group Pcmn with the lattice parameters a = 9.699 Å; b = 4.020 Å and c = 7.111 Å ​​and four formula units per unit cell.