Uneven, Uneven, Gemstones of the world (2001) More from other references
Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal to uneven
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references
Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references