Freieslebenite
Freieslebenite, also known as Basitomglanz, Donacargyrit, Dark Weißgültigerz or Schilfglaserz, is a rarely occurring mineral from the mineral class of sulfides and sulfosalts. It crystallizes in the monoclinic crystal system with the chemical composition PbAgSbS3 and developed prismatic, reed-like, crooked scale and typical for this mineral, parallel striped to the c- axis crystals whose color and stroke color of lead- gray to steel gray to silver white can range.
Etymology and history
Was first described in 1783 by Jean- Baptiste mineral Louis Romé de L' Isle, who describes it as mine d' argent antimoine grise tenant. In his description, L' Isle concentrated almost exclusively on the morphology of the crystals and their distinctive longitudinal stripes.
Since Johann Carl -free life was apparently not aware of the publication of L' Isle, he described the mineral in 1817 for a second time, went there primarily to its characteristics and gave him the name Schilfglaserz.
His final name Freieslebenite received the mineral in 1845 by Haidinger.
Classification
In the old ( 8th edition ) as the new classification of minerals ( 9th Edition ) by Strunz the Freieslebenite in the Department of sulfosalts is filed. The new system divides this department, however, still further, so that the mineral is now in the subsection " sulfosalts with PbS as a model and the Galena derivatives with lead (Pb) ".
The classification of minerals according to Dana assigns the Freieslebenite in the department of " sulfosalts with the general chemical composition z / y > 3 - ( A ) i ( A2 ) j [By Cz ], A = metals, B = semimetals, C = non-metals "
Education and Locations
Freieslebenite can be found in the pit Himmelsfürst at Freiberg in Saxony, Felsöbanya in Hungary and Hiendelaencina in Spain. It is formed hydrothermally.
Crystal structure
Freieslebenite crystallizes in the monoclinic space group P21 / a ( Raumgruppen-Nr. 14) with the lattice parameters a = 7.53 Å; b = 12.79 Å, c = 5.88 Å and β = 92.2 °, and four formula units per unit cell.