An arsenide of platinum occuring in grains and minute isometric crystals of tin-white color. It is found near Sudbury, Ontario Canada, and is the only known compound of platinum occuring in nature.

Sperrylite is a platinum arsenide mineral with formula: PtAs2 and is an opaque metallic tin white mineral which crystallizes in the isometric system with the pyrite group structure. It forms cubic, octahedral or pyritohedral crystals in addition to massive and reniform habits. It has a Mohs hardness of 6 - 7 and a very high specific gravity of 10.6.