Fibrous, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
Distinct on {100}, poor on {110}; parting on {001}
{0001} Imperfect, {1120} Imperfect
AlAl6O3BSi3O18
KCa 2AlBe 2Si 12O 30 · 0.5H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references