Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
CaBSiO 4(OH)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Ca 2B 5SiO 9(OH) 5Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references