ochre - Pigment, Industry

Earth consisting of a mixture of hydrated iron oxides and clay, light yellow to brown in colour. It is ground to a powder and used as a pigment.

For other uses, see Ocher.

Ochre or Ocher (pronounced /'əʊk.ə/, from the Greek ochros, yellow) is a color, usually described as golden-yellow or light yellow brown.

Pigment

As a painting pigment it exists in at least four forms:

Yellow ochre, Fe2O3 • H2O, a hydrated Iron oxide Red ochre, Fe2O3, chemically identical to yellow ochre, but reddened through heating Purple ochre, identical to red ochre chemically but of a different hue caused by different light diffraction properties associated with a greater average particle size Brown ochre (Goethite), also partly hydrated iron oxide (rust)

For further information, see the articles on the individual ochres. Many sources consider the best brown ochre to come from Cyprus, and the best yellow and red ochre from Roussillon, France.

Industry

When the mineral was found in Brixham it became a very important part of the developing fishing industry. It was boiled in great caldrons, together with tar, tallow and oak bark, the last ingredient giving the name of barking yards to the places where the hot mixture was painted on to the sails, which were then hung up to dry.

The ochre was also used to make a very special paint.