Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
Ca 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
KCa 2AlBe 2Si 12O 30 · 0.5H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references