Irregular/uneven, UnevenArthur Thomas, Gemstones (2009)
Uneven, Brittle, Metallic, Gemstones (2009)
CaAl 2Si 4O 12 -6H 2OArthur Thomas , Gemstones (2009)
Na 2[Al 2Si 3O 10] · 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references