Yellow, Blue, Black, Green, gray
Yellow, Red, Reddish, Brown, Colorless, White, Yellow, Red, Reddish, Brown, Colorless, White, gray, White, gray, Reddish, White, gray, Reddish, White, gray, Reddish
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Conchoidal, Uneven
Ca 2(Mg,Al) 6(Si,Al,B) 6O 20Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
KAl3(SO4)2(OH)6