UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Metallic
Brittle, Uneven
Mn2+ Zn 2SiO 4(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Mn2+5(PO 4) 2(PO 3OH) 2 · 4H 2O)Michael OâDonoghue , Gems, Sixth Edition (2006)