ocher

 

(ō'kər) , mixture of varying proportions of iron oxide and clay, used as a pigment. It occurs naturally as yellow ocher (yellow or yellow-brown in color), the iron oxide being limonite, or as red ocher, the iron oxide being hematite. Ocher grades into sienna, a yellow-brown pigment containing a higher percentage of iron ore than ocher as well as some manganese dioxide; sienna grades into umber, which is darker brown and contains a higher percentage of manganese dioxide. Burnt sienna is brown or bright red; burnt umber is a darker brown than umber. Ocher is produced in the United States, in France (French ocher being of a very high grade), and in some other parts of Europe. Italy is a leading producer of sienna and umber, and Cyprus of umber.

Ochre
<imagemap>Image:Information-silk.png|About these coordinates rect 0 0 50 50 About these coordinates desc none</imagemap>— Color coordinates —
Hex triplet		#CC7722
RGBB	(r, g, b)	(204, 119, 34)
HSV	(h, s, v)	(30°, 83%, 80%)
Source		[Unsourced]
B: Normalized to [0–255] (byte)

Ochre or Ocher (pronounced /'əʊ.kə(r)/, from the Greek ὠχρός, 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. 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 have been used since prehistoric times, and are among the oldest pigments used.

Industry

When the mineral was found in Brixham England, it became a very important part of the developing fishing industry. This gave the old fishing boats their "Red Sails in the Sunset", but the purpose was to protect the canvas from seawater, not to be picturesque. 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.

See also

• Clay earth pigment
• List of colors

External links

• Pigments through the ages
  • Red Ochre
  • Yellow ochre
  • Brown ochre

References

• 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.

					Shades of brown
Auburn	Bistre	Brown	Buff	Burgundy	Burnt sienna	Burnt umber	Copper	Liver	Mahogany	Maroon	Ochre
Pale brown	Raw Umber	Russet	Rust	Sandy brown	Seal brown	Sepia	Tan	Wheat	Zinnwaldite	Fallow	Bole
Taupe	Medium Taupe	Pale Taupe	Dark Khaki	Khaki	Light Khaki	Sandy Taupe	Ecru	Beige

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