White, Colorless, Blue, Red, Green, Yellow, Violet
Colorless, Green, Black, Brown, Red, Greenish, Yellow, gray
ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, Uneven, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
SiO 2Ulrich Henn and Claudio C.
Ca 3Fe 2(SiO 4) 3Arthur Thomas , Gemstones (2009)