Conchoidal, Brittle, Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
CaBSiO 4(OH)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references