Detailed information
Species
Kashinite, Isoferroplatinum, Laurite
Dimensions
16 x 16 x 4
mm
Locality
Baimka placer deposit Baimka River, Bol'shoi Anyui River Chukotka Autonomous Okrug, Russia
Condition
No recorded repairs
Sometimes rare species are extremely small, and here is a classic example. A single, 0.8 x 0.7 mm wide grain is mounted in a 15 mm diameter resin polished block, but this grain contains six extremely rare minerals - Kashinite, Laurite, Rutheniridosmine, Isoferroplatinum, 'Ni-Cu Kashinite' and an uncharacterized Iridium-Osmium-Ruthenium-Platinum 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 couple of old collection labels, the earliest of which, from Dr. Hans-Jurgen Wilke (1925-2014) records 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.
