Gems, Sixth Edition (2006), Gems, Sixth Edition (2006)
Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Metallic
SiO 2Michael OâDonoghue , Gems, Sixth Edition (2006)
PbCa 3Zn 4(SiO 4) 4Anthony et al , Handbook of mineralogy (2001)