Science Fair Project Encyclopedia
- yellow ochre, 3 • 2O, a hydrated Iron oxide
- red ochre, Fe2O3, chemically identical to yellow ochre, but reddened through heating
- brown ochre (Goethite), also partly hydrated iron oxide (rust)
For further information, see the articles on the individual ochres.
All ochres are non-toxic, and can be used to make oil paints that dry quickly and cover surfaces thoroughly. They are found throughout the world in many shades. Many sources consider the best brown ochre to come from Cyprus, and the best yellow and red ochre from Roussillon, France. All are prehistoric, and are some of oldest pigments used.
- Red Ochre, Yellow ochre, and Brown ochre, from Pigments through the ages.
- Fuller, Carl; Natural Colored Iron Oxide Pigments, pp. 281-6. In: Pigment Handbook, 2nd Edition. Lewis, P. (ed.). New York: John Wiley & Sons, 1988.
- Thomas, Anne Wall. Colors From the Earth, New York: Van Nostrand Reinhold, 1980.
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