Uneven, ConchoidalArthur Thomas, Brittle, Metallic
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Uneven
Pb 5(PO 4) 3ClArthur Thomas , Gemstones (2009)
Mn 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006)