Acanthite with Nickeline

A rare specimen of Acanthite and Nickeline from the polymetallic orebody at Měděnec in the Krušné Hory mountains o the Czech Republic.  The Acanthite forms relatively large and well developed equant crystals averaging around 5 mm diameter and of a metallic lead grey with a dull to silky lustre.  These sit within a vuggy, sponge-like matrix of grey-bronze Nickeline with a cellular, porous structure.  Acanthite was not commonly found at Měděnec, making this nicely crystallise specimen all the more interesting.