Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Mg 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Mg 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references