Uneven, UnevenArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalAnthony et al, Conchoidal, Brittle, Conchoidal
KCa 4Si 8O 20(F,OH) · 8H 2OUlrich Henn and Claudio C.
(Zn,Cu)Al 6(PO 4) 4(OH) 8 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)