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Earth Materials
Minerals | Rocks

Mineral Color
Allochromatic Color

A large number of minerals occur in a wide range of colors caused by impurities or light absorbing defects in the atomic crystal structure. Impurities are traces of elements (Cr, Mn, Fe, Ni, Cu...) that are not present in the pure mineral compound. Therefore allochromatic colors are variable and unpredictable mineral properties, eg. Tourmaline can be black, green or pink.

Idiochromatic Color
Crystal within crystals