Cobaltite from Tunaberg, Södermanland County, Sweden

Help improve this record

No owner is registered for this specimen yet. If it's yours or you know more about it, you can add the owner, provenance, publications and other details.

Cobaltite, or cobalt arsenic sulphide, is a silvery mineral with no recorded Type Locality. That is because it had been known for many centuries in Germany at numerous mines and was named in allusion to its presence of cobalt - cobalt itself referring to Kobalds: mischievous sprites or gremlins who were believed to have stolen the silver from this silvery coloured mineral and replaced it with poisonous arsenic. Roll forward a century or two and in the earliest years of the 19th century remarkably perfect crystals of this mineral were discovered in Sweden at Tunaberg and Håkansboda and the great and good of mineralogical research descended upon the mines to acquire crystals. This individual crystal is a perfectly formed combined octahedron and pyritohedron measuring 11.5 mm across in its widest dimension. Complete all around, it is what we would terms a 'floater', and it maintains a very bright silvery metallic lustre. Ex David Hardman collection, no. 8846.