Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
Not Available
CaBSiO 4(OH)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Mn2+9(SiO 4) 4(OH,F) 2Anthony et al , Handbook of mineralogy (2001)