Ethiopia, Mexico, Honduras, Guatemala, Brazil, USA, Canada, Madagascar, Tanzania, Czech, Slovakia
Australia, Southern and central Africa
Not Available
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Uneven
Not Available
Mg 6Cr 2(CO 3)(OH) 16 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references