Colorless, Yellow, Brown, Green, Colorless, Green, Yellow, Red, Reddish, Brown
Colorless, Greenish, Colorless, Green, gray, Yellow
Brittle, Metallic, Brittle, Metallic
Irregular/uneven, Uneven
Ca(Mg,Al)3(Al3Si)O10(OH)2
Ca 2Al 3(SiO 4) 3(OH)Walter Schumann , Gemstones of the world (2001) More from other references