Detailed information
Species
Kashinite, Laurite, Rutheniridosmine
Dimensions
16 x 16 x 6
mm
Weight
3 g
Locality
Baimka placer deposit Baimka River, Bol'shoi Anyui River Chukotka Okrug, Russia
Condition
No recorded repairs
A single, 1.3 x 0.9 mm wide grain is mounted in a 16 mm diameter resin polished block, but this grain contains six extremely rare minerals - Kashinite, Laurite, Rutheniridosmine, Isoferroplatinum, an uncharacterized Iridium-Osmium-Platinum alloy and an uncharacterized Platinum-Ruthenium-Osmium-Iridium alloy. This style of polished mount requires a specialist reflected light microscope in order to study the grains and the reflectance produced by these metallic minerals under plane polarized and cross polarized light. Often, even optical identification is a challenge and the carbon coating on the edge of this polished block shows that it has been studied chemically using a Scanning Electron Microscope. This is not our usual type of specimen, but included due to its rarity. Examples of these rare species from this occurrence at the Baimka placer deposit in the far east of Russia are few and far between. This sample comes with a previous printed collection label from Austria, but it was also owned by Dr. Hans-Jurgen Wilke (1925-2014) whose record card (which is allocated to a separate Kashinite specimen) notes that it was obtained in 1993 from Dr. Mikhail Murashko in St. Petersburg, Russia. The overall measurements provided indicate the size of the polished block.
