Gemstones (2009), Flexible Flexible fragments.
Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
Al 2Si 4O 10(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
CaBSiO 4(OH)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references