Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
Subconchoidal, Uneven, Conchoidal, Uneven
CuSiO 2(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Mn2+ Al(PO 4)(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)