UnevenAnthony et al, Handbook of mineralogy (2001) More from other references, UnevenAnthony et al, Handbook of mineralogy (2001) More from other references, Brittle, Metallic
Gems, Sixth Edition (2006)
CoAsSAnthony et al , Handbook of mineralogy (2001)
Quartz: SiO2 Rutile: TiO2