Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
K(Ca,Na) 2Si 4O 10(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Mg 2Si 2O 6Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references