Samsonite (mineral)
Samsonit is a very rarely occurring mineral from the mineral class of sulfides, specifically a sulfosalt. It crystallizes in the monoclinic crystal system with the chemical formula Ag4MnSb2S6 and developed opaque, prismatic and striped up to three inches large crystals of steel-gray to black in color.
Etymology and history
The mineral was first found in 1910 by mountain inspector Heinrich Werner to a depth of 550 meters in the Samson mine in Sankt Andreas mountain in the Upper Harz. The mineral was named after the type locality.
Classification
In the old ( 8th edition ) and the new classification of minerals according to Strunz ( 9th Edition ) Samsonit the mineral class of sulfides and sulfosalts is assigned. However, while the old system the Pyrargyrite assigns the sulfosalts without further subdivision along with Proustite, Pyrostilpnit, Quadratit, Pyrargyrite and Xanthokon, more divisions and subdivisions were created in the new classification, so that the mineral is now in a separate sub-group of the Department of " Sulfoarsenide, Sulfoantimonide, Sulfobismuthide " and the subsection " island ( Neso ) Sulfarsenide, etc. is without additional sulfur " in a group.
In the scheme of minerals by Dana Samsonit forms a subgroup of sulfosalts with the ratio z / y > 3 and the composition (A ) i ( A2 ) j [ Bycz ], A = metals, B = semimetals, C = non-metals.
Education and Locations
Samsonit formed hydrothermally, as accompanying minerals can Apophyllite and Dyscrasite, galena, calcite, Pyrargyrite, pyrolusite, quartz and tetrahedrite occur.
As the first and most important locality, the Samson Pit, St. Andrew Mountain / Upper Harz is to call in Germany. In addition, Samsonit still found in Garpenberg Sweden, Cobalt in Canada, Pribram in the Czech Republic and Candelaria in the U.S. state of Nevada.
Crystal structure
Samsonit crystallizes in the monoclinic crystal system, space group P21 / n with lattice parameters a = 10.36 Å, b = 8.10 Å, c = 6.65 Å and β = 92.38 ° and two formula units per unit cell. The manganese atoms are oktadedrisch of six sulfur atoms, the antimony atoms of three sulfur atoms surrounded trigonal pyramidal. The silver atoms come in two different positions in the crystal before, one part is distorted tetrahedral surrounded by four sulfur atoms, the other part trigonal planar three sulfur atoms.