Uneven, UnevenArthur Thomas, Gemstones (2009), Brittle
UnevenAnthony et al, Handbook of mineralogy (2001) More from other references, UnevenAnthony et al, Handbook of mineralogy (2001) More from other references, Brittle, Metallic
MnPO 4Walter Schumann , Gemstones of the world (2001) More from other references
CoAsSAnthony et al , Handbook of mineralogy (2001)