Sperrylite

This specimen features a sharp, well-formed cube-octahedral crystal of sperrylite, partially embedded yet well-exposed in matrix. The crystal displays mirror-bright, highly reflective faces, making it an excellent example of this rare platinum arsenide mineral. The matrix also contains the remnants of a much larger crystal—now only partially preserved, with half embedded in the surrounding rock.

Sperrylite was first discovered in 1889 by Francis Lewis Sperry, a chemist from Sudbury, Ontario, for whom the mineral is named. As an important ore of platinum, sperrylite is one of the few naturally occurring platinum-containing minerals. Specimens of this quality, with well-defined crystal structure are highly prized amongst collectors.