Conchoidal, ConchoidalAnthony et al, Conchoidal, Brittle, Conchoidal
Gemstones (2009), Flexible Flexible fragments.
(Zn,Cu)Al 6(PO 4) 4(OH) 8 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
Al 2Si 4O 10(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references