Brittle, Metallic
UnevenAnthony et al, Handbook of mineralogy (2001), UnevenAnthony et al, Handbook of mineralogy (2001)
◻(LiAl 2)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)
Na(Mn2+ ,Ca) 2Si 3O 8(OH)Michael OâDonoghue , Gems, Sixth Edition (2006)