Yellow, Red, Reddish, Brown, Colorless, White, Yellow, Red, Reddish, Brown, Colorless, White, gray, White, gray, Reddish, White, gray, Reddish, White, gray, Reddish
Red, Yellow, Red, orange
Conchoidal, Uneven
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), (e.g. graphite).