UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Gemstones (2009), Flexible Flexible fragments.
BaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Al 2Si 4O 10(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references