Brown, Brown, Reddish, Brownish, Yellow, Brown, Reddish, Brownish, Yellow
White, Colorless, Blue, Red, Green, Yellow, Violet
Uneven, torn surfaces, (e.g. fractured metals)., Uneven, Gemstones (2009), torn surfaces, (e.g. fractured metals).
Not Available
FeO(OH)Arthur Thomas , Gemstones (2009)
SiO 2Ulrich Henn and Claudio C.