ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Brittle, Metallic, Gemstones (2009)
[C,H,O]
Na 2[Al 2Si 3O 10] · 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references