UnevenAnthony et al, Uneven, UnevenAnthony et al, Uneven, Brittle, Metallic
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
NaCaB 5O 6(OH) 6 · 5H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)
Fe 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)