Uneven, Conchoidal, UnevenArthur Thomas, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Uneven
Fe2+ CO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Mg 3Al 6(Si,Al,B) 5O 21(OH)Walter Schumann , Gemstones of the world (2001) More from other references