Brownish, Black
Colorless, Reddish, White, pink, Green, Yellow, Violet, White, pink, Green, Yellow, Violet, White, Colorless, Blue, Green, Brown, Yellow, pink, Violet, White, pink, Green, Yellow, Violet
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
Uneven, UnevenArthur Thomas, Gemstones (2009)
NaFe3+3Fe3+6(BO 3) 3Si 6O 18(O,OH) 4Anthony et al , Handbook of Mineralogy (2001)
KCa 4Si 8O 20(F,OH) · 8H 2OUlrich Henn and Claudio C.