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