Blue, Yellow, Brown, gray, Reddish, Greenish
Yellow, Greenish, Brownish, Colorless, White, gray, Green, Blue, Violet, orange
(e.g. graphite).
Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
{???} Imperfect, {???} Imperfect
[001] good, [210] distinct