Uneven, Conchoidal, Brittle, Metallic, ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
Ca 3Cr 2(SiO 4) 3Ulrich Henn and Claudio C.
K(Ca,Na) 2Si 4O 10(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references