Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal to uneven
Uneven, Conchoidal, UnevenWalter Schumann, Gemstones of the world (2001)
[0001] indistinct, [1010] indistinct
Perfect {010}, imperfect {100}
Ca 5(PO 4) 3(F,OH,Cl)Walter Schumann , Gemstones of the world (2001) More from other references
Ca2Al3(SiO4)3(OH)