Ochre (/ˈoʊkər/OH-kər; from Greek: ὠχρός, ōkhrós, (pale yellow, pale), also spelled ocher, see spelling differences) is a natural earth pigment containing hydrated iron oxide, which ranges in color from yellow to deep orange or brown. It is also the name of the colors produced by this pigment, especially a light brownish-yellow.[1][2] A variant of ochre containing a large amount of hematite, or dehydrated iron oxide, has a reddish tint known as "red ochre".

Ochre and the earth pigments[edit]

Ochre is a family of earth pigments, which includes yellow ochre, red ochre, purple ochre, sienna, and umber. The major ingredient of all the ochres is iron(III) oxide-hydroxide, known as limonite, which gives them a yellow color.

Sienna contains both limonite and a small amount of manganese oxide (less than five percent), which makes it darker than ochre.

Umber pigments contain a larger proportion of manganese (five to twenty percent) which make them a dark brown.[3]

When natural sienna and umber pigments are heated, they are dehydrated and some of the limonite is transformed into hematite, giving them more reddish colors, called burnt sienna and burnt umber.

Ochres are non-toxic, and can be used to make an oil paint that dries quickly and covers surfaces thoroughly.

Modern ochre pigments often are made using synthetic iron oxide. Pigments which use natural ochre pigments indicate it with the name PY-43 (Pigment yellow 43) on the label, following the Color Index International system.

Limonite, a mineraloid containing iron hydroxide, is the main ingredient of all the ochre pigments.

Hematite is a more reddish variety of iron oxide, and is the main ingredient of red ochre. When limonite is roasted, it turns partially to the more reddish hematite and becomes red ochre or burnt sienna.

Goethite, named for the German poet Goethe, is the main ingredient of brown ochre. This sample comes from the Leadville District in Colorado.

Use in history, art and culture[edit]

Prehistory and early history[edit]

"The use of ocher is particularly intensive: it is not unusual to find a layer of the cave floor impregnated with a purplish red to a depth of eight inches. The size of these ocher deposits raises a problem not yet solved. The colouring is so intense that practically all the loose ground seems to consist of ocher. One can imagine that the Aurignacians regularly painted their bodies red, dyed their animal skins, coated their weapons, and sprinkled the ground of their dwellings, and that a paste of ocher was used for decorative purposes in every phase of their domestic life. We must assume no less, if we are to account for the veritable mines of ocher on which some of them lived..."

Iron oxide is one of the most common minerals found on earth, and there is much evidence that yellow and red ochre pigment was used in prehistoric and ancient times by many different civilizations on different continents. Pieces of ochre engraved with abstract designs have been found at the site of the Blombos Cave in South Africa, dated to around 75,000 years ago.[4]

Paintings of animals made with red and yellow ochre pigments have been found in neolithic sites at Pech Merle in France (ca. 25,000 years old), and the cave of Altamira in Spain (ca. 15,000-16,500 BC). The cave of Lascaux has an image of a horse colored with yellow ochre estimated to be 17,300 years old.

According to some scholars, Neolithic burials used red ochre pigments symbolically, either to represent a return to the earth or possibly as a form of ritual rebirth, in which the color symbolizes blood and the Great Goddess.[5]

In Ancient Egypt, yellow was associated with gold, which was considered to be eternal and indestructible. The skin and bones of the gods were believed to be made of gold. The Egyptians used yellow ochre extensively in tomb painting, though occasionally they used orpiment, which made a brilliant color but was highly toxic, since it was made with arsenic. In tomb paintings, men were always shown with brown faces, women with yellow ochre or gold faces.[6]

Red ochre in Ancient Egypt was used as a rouge, or lip gloss for women.[7] Ocher-colored lines were also discovered on the Unfinished Obelisk at the northern region of the AswanStone Quarry, marking work sites. Ochre clays were also used medicinally in Ancient Egypt: such use is described in the Ebers Papyrus from Egypt, dating to about 1550 BC.

Ochre was the most commonly used pigment for painting walls in the ancient Mediterranean world. In Ancient Greece, red ochre was called μίλτος, míltos (hence Miltiades, red-haired or ruddy). In Athens when Assembly was called, a contingent of public slaves would sweep the open space of the Agora with ropes dipped in miltos: those citizens that loitered there instead of moving to the Assembly area would risk having their clothes stained with the paint. This prevented them from wearing these clothes in public again, as failure to attend the Assembly incurred a fine.

In classical antiquity, the finest red ochre came from a Greek colony on the Black Sea where the modern city of Sinop in Turkey is located. It was carefully regulated, expensive and marked by a special seal, and this color was called sealed Sinope. Later the Latin and Italian name sinopia was given to wide range of dark red ochre pigments.[8] The Romans used yellow ochre in their paintings to represent gold and skin tones, and as a background color. It is found frequently in the murals of Pompeii.

Yellow ochre was often used in wall paintings in Ancient Roman villas and towns.

Ochre in the Renaissance[edit]

During the Renaissance, yellow and red ochre pigments were widely used in painting panels and frescoes. The colors vary greatly from region to region, depending upon whether the local clay was richer in yellowish limonite or reddish hematite. The red earth from Pozzuoli near Naples was a salmon pink, while the pigment from Tuscany contained manganese, making it a darker reddish brown called terra di siena, or Siana earth.[9]

The 15th century painter Cennino Cennini described the uses of ochre pigments in his famous treatise on painting. "This color is found in the earth in the mountains, where there are found certain seams resembling sulphur; and where the seams are, there is found sinoper, and terre-verte, and other kinds of color... And these colors showed up in this earth just the way a wrinkle shows up in the face of a man or woman.... I picked out the wrinkle of this color with a pen knife, and I do assure you that there never was a better color. And know that this ochre is an all-round color, especially for work in fresco; for it is used, with other mixtures, as I shall explain to you, for flesh colors, for draperies, for painted mountains, and buildings and horses, and in general for many purposes."[10]

Modern history[edit]

The industrial process for making ochre pigment was developed by the French scientist Jean-Étienne Astier in the 1780s. He was from Roussillon in the Vaucluse department of Provence, and he was fascinated by the cliffs of red and yellow clay in the region. He invented a process to make the pigment on a large scale. First the clay was extracted from open pits or mines. The raw clay contained about 80 to 90 percent sand and 10 to 20 percent ochre. Then he washed the clay to separate the grains of sand from the particles of ochre. The remaining mixture was then decanted in large basins, to further separate the ochre from the sand. The water was then drained, and the ochre was dried, cut into bricks, crushed, sifted, and then classified by color and quality. The best quality was reserved for artists' pigments.[3]

In Britain, ochre was mined at BrixhamEngland. It became an important product for the British fishing industry, where it was combined with oil and used to coat sails to protect them from seawater, giving them a reddish color. The ochre 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. Seal oil mixed with the ochre gave the sails a purer red color, while cod liver oil would give a "foxy" color, browner in hue.

As noted above, the industrial process for making ochre pigment was developed by the French scientist Jean-Étienne Astier in the 1780s, using the ochre mines Roussillon in the Vaucluse department of Provence, in France. Thanks to the process invented by Astier and refined by his successors, ochre pigments from Roussillon were exported across Europe and around the world. It was not only used for artists paints and house paints; it also became an important ingredient for the early rubber industry.

Ochre from Roussillon was an important French export until the mid-20th century, when major markets were lost due to the Russian Revolution and the Spanish Civil War. Ochre also began to face growing competition from newly synthetic pigment industry. The mines in Roussillon closed, though the production of natural ochre pigments continued at mines in Cyprus and other sites.

In Australia and New Zealand[edit]

Ochre has been used for millennia by Aboriginal people in Australia and by natives in New Zealand for body decoration, mortuary practices, cave painting, bark painting and other artwork, and the preservation of animal skins, among other uses. At Lake Mungo, in Western New South Wales, burial sites have been excavated and burial materials, including ochre-painted bones, have been dated to the arrival of people in Australia[11] Ochre pigments are plentiful across Australia, especially the Western Desert, Kimberley and Arnhem Land regions, and occur in many archaeological sites.[12] The National Museum of Australia has a large collection of samples of ochre from many sites across Australia.[13]

The Maori people of New Zealand were in the early neolithic period of development when Europeans arrived, and were found to be making extensive use of mineral ochre mixed with fish oil. Ochre was the predominant coloring agent used by Maori, and was used to paint their large waka taua (war canoe). Ochre prevented the drying out of the wood in canoes and the carvings of meeting houses; later missionaries estimated that it would last for 30 years. It was also roughly smeared over the face, especially by women, to keep off insects. Solid chunks of ochre were ground on a flat but rough surfaced rock to produce the powder.

In North America[edit]

In Newfoundland[14] its use is most often associated with the Beothuk, whose use of red ochre led them to be referred to as "Red Indians" by the first Europeans to Newfoundland.[15] It was also used by the Maritime Archaic as evidenced by its discovery in the graves of over 100 individuals during an archaeological excavation at Port au Choix. Its use was widespread at times in the Eastern Woodlands cultural area of Canada and the US; the Red Ocher people complex refers to a specific archaeological period in the Woodlands ca. 1000-400 BC. California Native Americans such as the Chumash were also known to use red ochre as body paint.[16]

In Newfoundland, red ochre was the pigment of choice for use in vernacular outbuildings and work buildings associated with the cod fishery. Deposits of ochre are found throughout Newfoundland, notably near Fortune Harbor and at Ocher Pit Cove. While earliest settlers may have used locally collected ochre, people were later able to purchase pre-ground ochre through local merchants, largely imported from England.

The dry ingredient, ochre, was mixed with some type of liquid raw material to create a rough paint. The liquid material was usually seal oil or cod liver oil in Newfoundland and Labrador, while Scandinavian recipes sometimes called for linseed oil. Red ochre paint was sometimes prepared months in advance and allowed to sit, and the smell of ochre paint being prepared is still remembered by many today.

Variations in local recipes, shades of ore, and type of oil used resulted in regional variations in color. Because of this, it is difficult to pinpoint an exact shade or hue or red that would be considered the traditional "fishing stage red". Oral tradition in the Bonavista Bay area maintains

In Africa[edit]

Women of the Himba ethnic group in Namibia are famous for using a mix of ochre and animal fat for body decoration, to achieve a reddish skin color. The ochre mixture is also applied to their hair after braiding.[17]

See also[edit]

Notes and citations[edit]

^The Random House College Dictionary, Revised Edition, (1980). "Any of a class of natural earths, mixtures of hydrated oxides of iron and various earthy materials, ranging in color from pale yellow to orange and red, and used as pigments. A color ranging from pale yellow to reddish-yellow."

^Giulia Battiti Sorlini, "The Megalithic Temples of Malta", Por Anthony Bonanno, Archaeology and fertility cult in the ancient Mediterranean: papers presented at the First International Conference on Archaeology of the Ancient Mediterranean, University of Malta, 2–5 September 1985, p.145.