Colorless, Green, Black, Brown, Red, Greenish, Yellow, gray
Colorless, Yellow, Brown, Green, Red, Reddish
Conchoidal, Uneven, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
Brittle, Metallic
Ca 3Fe 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
Ca(Mg,Al)3(Al3Si)O10(OH)2