Splintery, Granular, Splintery, Granular, Gemstones (2009)
Uneven, ConchoidalArthur Thomas, Brittle, Metallic
Ca 2(Mg,Fe) 5(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references
Pb 5(PO 4) 3ClArthur Thomas , Gemstones (2009)