Polarite

• IMA 1969-032

Polarity is a very rarely occurring mineral from the mineral class of sulfides and sulfosalts. It crystallizes in the orthorhombic crystal system with the chemical composition Pd2PbBi and constitutes up to 0.3 mm grain of white color with a yellowish tint.

Etymology and history

The mineral was in 1969 by A.D. Genkin, T. L. Jewstignejewa, N.W. Tronewa, and L.N. Wjalsow in the type locality, the Mayak mine found near Norilsk in Russia. The mineral is named after the Polar Urals, the northernmost mountain range of the Urals, in which the type locality is located.

Classification

In the classification by Strunz polarity is counted among the sulfides and sulfosalts. After the 8th edition forms together with Breithauptit, Cherepanovit, Freboldit, Hexatestibiopanickelit, Kotulskit, Nickeline, Langisit, Ruthenarsenit, Sederholmit, Sobolevskit, Sorosit, Stumpflit and Sudburyite a subset of the sulfides with a ratio of metal to sulfur, selenium or tellurium from 1:1. In the 9th edition, it forms its own sub-group of compounds of semi-metals with platinum - group elements (PGE ).

In the classification by Dana, it forms a separate subgroup of the sulfides, selenides and tellurides with the composition AmBn Xp, with (m n): p = 1:1.

Education and Locations

Polarity is formed under hydrothermal conditions in copper - nickel-iron cores. It is associated with chalcopyrite, Talnakhit, cubanite, Stannopalladinit, Paolovit, Sobolevskit, Sperrylit, Cabriit, Palarstanid, sphalerite and silver.

From the very rare mineral only a few localities are known. In addition to the type locality was found polarity in Longhua in China's Hebei Province, on Lake Onega in Russia and in Goodnews Bay in the U.S. state of Alaska.

Crystal structure

Polarity crystallizes in the orthorhombic crystal system, space group Ccm21 or with the lattice parameters a = 7.191 Å, b = 8.693 Å and c = 10.681 Å and 16 formula units per unit cell.