Conchoidal, Metallic, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Uneven, UnevenArthur Thomas, Gemstones (2009)
Cu 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Mg 3Si 4O 10(OH) 2Ulrich Henn and Claudio C.