Colorless, Greenish, Colorless, Green, gray, Yellow
Yellow, Brownish, Reddish, Green, Brownish, Yellow, Green, Yellow, Red
Ca 2Al 3(SiO 4) 3(OH)Walter Schumann , Gemstones of the world (2001) More from other references
(Fe+++,Al)25(PO4)17O6(OH)12•75(H2O)