Sperrylite

This specimen features a sharp, well-formed cube-octahedral sperrylite crystal (possibly twinned?), partially embedded yet well-exposed in the matrix. The crystal boasts mirror-bright, reflective faces across much of its surface, making it a great example of this rare platinum arsenide mineral.

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.