Inorganic chemicals as colours

An example of a cave painting -a bison — found at Altamira, northern Spain. 

Iron oxides, which were undoubtedly components of these prehistoric paints, still find application today as low-cost, low-toxicity pigments in paint, plastics, rubbers and cosmetics. The three main colours available are red (haematite-, Fe203), yellow (goethite FeO.OH) and black (magnetite-, Fe304), and other colours can be produced by blending these three. The oxides are generally prepared by precipitation from aqueous solution  

The iron (II) sulfate is often obtained as a by-product from steel pickling or titanium dioxide manufacture. 

Lead compounds have also been widely used as pigments. Lead chromate, PbCr04, is the yellow pigment used in the double yellow lines on roads. White lead, 

Pb(OH)2 was for many years the pigment of choice for white paint. 

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