Mars Yellow Dispersion

Rublev Colours Mars Yellow Aqueous Pigment Dispersion is an intense ocherous yellow color that makes warm yellowish tints. Mars colors are permanent pigments with good tinting strength in all mediums. Mars yellow, originally named jaune de Mars in the eighteenth century, is a high-tinting iron oxide pigment. The pigment’s very fine particle size gives it an intense color.

Origin and History

Mars Yellow is one of the Mars pigments developed during the eighteenth century and manufactured by the aqueous precipitation of iron salts. Mars yellow is the first pigment produced by this process, which is then further roasted to produce the other Mars colors—orange, brown, red, and violet. Unlike other synthetic iron oxides and oxide hydroxides, the Mars colors were pure and fine-grained while retaining high tinting strength. Mars yellow is a yellow-brown shade. Mixing the iron sulfate raw material with alum could be brightened to a pale yellow before precipitating the iron oxide.

In his 1869 edition of George Field’s Chromatography, Salter gives Jaune de Mars, Jaune de Fer, and Iron yellow as synonyms for Mars yellow, adding that it was sometimes adulterated with orpiment or lead chromate to brighten the color.

Source

The first Mars pigments were manufactured by precipitating iron(II) sulfate (also called ‘green vitriol’ or ‘martial vitriol’) mixed with alum with an alkali, such as lime, caustic soda, potash, etc. The residue was then washed carefully to remove any remaining salts. Other salts of iron (iron chloride, iron nitrate, or iron acetate) were also used to manufacture the pigment. The precipitation of iron salts and alkali produced a yellow-brown pigment. Alum was added to iron sulfate to produce a light yellow pigment. Mars yellow was the starting material for other Mars colors.

Permanence and Compatibility

Like all iron oxide pigments, Mas yellow is lightfast in all mediums and shows excellent weatherability.

Oil Absorption and Grinding

Mars yellow requires a moderate amount of oil, about 25 to 35 grams of linseed oil per 100 grams of pigment to make a paste with this pigment.

Toxicity

Mars yellow is not considered toxic; however, care should be taken when handling the dry powder pigment to avoid inhaling the dust. This pigment is approved by the FDA. All toxicological studies showed no signs of toxicity to humans or the environment. It is for use in polymeric food contact articles regulated under the Code of Federal Regulations, 21 CFR Part 178.3297 “Colorants for Polymers” 4.1.13.

Ecology

Since Mars yellow is inert and practically insoluble in water, it does not pose a hazard to the environment. The pigment can be removed mechanically from effluents, and no dissolved heavy metals are released into the seepage water on controlled dumpsites.

For more information on handling pigments safely, please visit How to Safely Handle Art Materials and Pigments.

For a detailed explanation of the terms in the table above, please visit Composition and Permanence.