This color contains the following pigments:
iron(III)-oxide, partly hydrated
Brown Ochre provides artists with earthtones from cream to brown and is a dull, dark variety of Yellow Ochre. Its transparency varies widely from opaque shades to more transparent ones, which are valued for their use as glazes. It has good hiding power, produces a quick drying paint, and can be safely mixed with other pigments. The highest quality Brown Ochre comes from Cyprus, where it is yellow in its raw form and is roasted to get the deeper brown-red varieties that result when water is removed. (See Yellow Ochre, PY42/43.)
Brown Ochre has excellent permanence.
Brown Ochre is non-toxic.
Ochre comes from the Greek word ochros, meaning pale yellow. It has been used since prehistoric times, and evidence of its use has been found in some of the earliest known cave paintings in Lascaux, France. It has also been called Goethite, after the German philosopher and mineralogist Johann Wolfgang von Goethe (1749-1832).
Fe2O2 or Fe2O3 • H2O
Mars Orange is a bright, extremely light red and appears almost pinkish when contrasted with darker colors. It has incredible tinting strength and opacity. The synthetic form of Mars Orange is made from iron oxides and is cleaner, brighter, and denser than its ochre-based counterparts.
Mars Orange has good permanence and lightfastness.
Mars Orange has no significant hazards.
The word Mars refers to the Roman god of iron and war. Mars Orange has been manufactured as a pigment since the 17th century.