Crystal System: Hexagonal
Status of Occurrence: Unconfirmed Occurrence
Distribution: Rare
Chemical Composition: Osmium
Chemical Formula: Os
Method(s) of Verification: none.

Chemical Group:

  • Elements & Alloys

Geological Context:

  • Igneous
  • Hydrothermal: mesothermal polymetallic veins
  • Sedimentary
Introduction: osmium occurs with other platinum-group metals in magmatic segregation deposits and occasionally in certain hydrothermal vein associations. It is also found in the sedimentary environment, within placer deposits in platinum-bearing districts.
Occurrence in Wales: osmium is one of a number of minerals that were reported from the Dolgellau Gold-belt by Readwin (1888). It was said to be present as 'detrital iridosmine', occurring in the placer deposits of the Afon Mawddach and Afon Gain in association with platinum and gold. As with many of these minerals, it has not been observed since. Given the amount of prospecting work done in the area in the past 90 years it is necessary to treat this report with caution.

Key Localities:

There are no key localities for this specimen.


  1. Readwin, T.A., 1888. Gold in Wales. London, 12pp.