Baumhauerite
Baumhauerite is a very rare mineral that is seen embedded in dolomitic marble/ It is found primarily in the Lengenbach quarry, Binnetal, in the Valais region of Switzerland. The mineral is named after Heinrich Baumhaumer, who discovered it at Lengenbach in 1902. The Lengenbach quarry is famous among mineralogists for its array of rare minerals. Baumhauerite has also been at Sterling Hill, New Jersey, USA, typically in asssociation with molybdenite, and in aggegastes at Hemlo, Thunder Bay, Ontario, Canada. It's color is gray-black to blue-gray and it's lustre is metallic to dull. Baumhauerite has a hardness of a 3.