Lazulite

Lazulith, as Blauspat (h) or less often than Gersbyit or Klaprothin known, is a rarely occurring mineral from the mineral class of phosphates. It crystallizes in the monoclinic crystal system with the chemical composition MgAl2 (PO4) 2 (OH ) 2 and usually develops short prismatic or bipyramidal crystals, but also granular to massive mineral aggregates of pale blue to blue-black, blue-green or yellow-green color. Well-developed crystals are often transparent to translucent and show on their faces vitreous luster.

Etymology and history

The name Lazulith is derived from the Arabic word for sky and makes reference to the mostly blue color of the mineral. First described it in 1791 by JFW Wide husband and four years later again by Martin Heinrich Klaproth.

As a type locality applies Freßnitzgraben at Krieglach in Austria.

Classification

In the old ( 8th edition ) and new classification of minerals according to Strunz ( 9th edition ) of the Lazulith belongs to the department of " water clear phosphates with foreign anions ." The new Strunz'sche Mineral classification divided here but now more specific on the size of the cations and by the molar ratio of the involved anions and the phosphate, arsenate or Vanadatkomplex and the mineral is in accordance with the subdivision "With only medium-sized cations, and the molar ratio ( OH, etc.): RO 4 ≥ 1: 1 "

The classification of minerals according to Dana sorted the Lazulith in the department of " water clear phosphates, etc. with hydroxyl or halogen, and the general formula ( A2 B2 ) 3 ( XO4 ) 2ZQ ".

Education and Locations

Lazulith forms secondarily by hydrothermal processes of primary phosphate minerals in quartz veins or Granitpegmatiten. Accompanying minerals are adjacent to the quartz or andalusite, berlinite, beryl, corundum, kyanite, muscovite, pyrophyllite, rutile, and many others.

So far Lazulith could be detected in 158 localities, so among other things in Bundaberg and Mount Lofty Ranges ( South Australia ) in Australia; in the Bolivian department of Cochabamba, La Paz and Potosí; Bahia and Minas Gerais in Brazil; Copiapó in Chile; Fujian in China; Orivesi in Finland; Bayern (Bavarian and Upper Palatinate Forest ) and Thuringia ( Thuringian Forest) in Germany; in some regions of Italy; on Honshu in Japan; Yukon in Canada; in Antsirabe and Amoron'i Mania in Madagascar; Hedmark and Nordland in Norway; Hollenthon (Lower Austria ), Hohe Tauern (Salzburg), Fischbach and war Lach ( Styria) in Austria; Gilgit ( district ) in Pakistan; Torre de Ferreira de Aves Moncorvo and in Portugal; Gatumba in Rwanda; Eastern Siberia and the Komi in Russia; Skåne, Värmland and Västergötland in Sweden; in the Swiss cantons of Graubünden and Valais; Košice and Nitra in Slovakia; in Cadaqués in Spain; Bohemia in the Czech Republic; at Erdőbénye and Sopron in Hungary; as well as in many regions of the United States.

Crystal structure

Lazulith crystallizes in the monoclinic crystal system, space group P 21 / c with lattice parameters a = 7.144 Å; b = 7.278 Å, c = 7.228 Å and β = 120.51 ° and two formula units per unit cell.