ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
Conchoidal, ConchoidalAnthony et al, Conchoidal, Brittle, Conchoidal
Al 2Be 3Si 6O 18Martin H.
(Zn,Cu)Al 6(PO 4) 4(OH) 8 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)