Uneven
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Metallic
K(Al,Cr) 3Si 3O 10(OH) 2Gemdat.org , Management Team (2012)
Mn2+ Zn 2SiO 4(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references