Uneven, Conchoidal to uneven, Brittle, Metallic, Uneven, ConchoidalWalter Schumann, Brittle, Metallic
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Distinct on {110}, imperfect on {010}, poor on {001}
Vitreous, pearly on cleavage
BeAl 2 O 4
(Fe2+ ,Mg,Mn2+ ) 3(PO 4) 2 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references