Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Perfect on {110}, poor on {101}, {001} rare
Distinct on {100} and {110}
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
3NaAlSi 3O 8 · NaClAnthony et al , Handbook of mineralogy (2001)