ochre

Information about ochre

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)


This article is about the color. For other uses, see Ochre (disambiguation).
For other uses, see Ocher.


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

Enlarge picture
Goethite (brown ochre)
Enlarge picture
Ochre quarry of Rustrel


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

External links

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.
   
AuburnBistreBrownBuffBurgundyBurnt siennaBurnt umberCopperLiverMahoganyMaroonOchre
            
Pale brownRaw UmberRussetRustSandy brownSeal brownSepiaTanWheatZinnwalditeFallowBole
            
TaupeMedium TaupePale TaupeDark KhakiKhakiLight KhakiSandy TaupeEcruBeige
         
RGB color model is an additive model in which red, green, and blue (often used in additive light models) are combined in various ways to reproduce other colors. The name of the model and the abbreviation ‘RGB’ come from the three primary colors, red, green, and blue and
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Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 625–750 nm.
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Green is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nm. It is considered one of the additive primary colors.
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The term blue may refer to any of a number of similar colours. The sensation of blue is made by light having a spectrum dominated by energy in the wavelength range of about 440–490 nm.
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HSL and HSV (also called HSB) are two related representations of points in an RGB color space, which attempt to describe perceptual color relationships more accurately than RGB, while remaining computationally simple.
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Hue is one of the three main attributes of perceived color, in addition to lightness and chroma (or colorfulness). Hue is also one of the three dimensions in some colorspaces along with saturation, and brightness (also known as lightness or value).
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colorfulness, chroma, and saturation are related concepts referring to the intensity of a specific color. More technically, colorfulness is the perceived difference between the color of some stimulus and gray, chroma
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Brightness is an attribute of visual perception in which a source appears to emit a given amount of light. In other words, brightness is the perception elicited by the luminance of a visual target. This is a subjective attribute/property of an object being observed.
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Ochre may refer to:
  • Ochre, the golden-yellow color
  • Ochre (musician), the stage name of electronic musician Chris Leary
  • Ochre, the stop codon UAA in classical genetics
  • Ochre River, Manitoba, in Canada

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Ocher or Ochyor may refer to:
  • Ochre, also spelled ocher, a color
  • Ochyor, a town in Perm Krai, Russia
  • Ochyor River, a river in Russia
  • Ochre River, Manitoba, Canada

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Greek}}} 
Writing system: Greek alphabet 
Official status
Official language of:  Greece
 Cyprus
 European Union
recognised as minority language in parts of:
 European Union
 Italy
 Turkey
Regulated by:
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Color or colour[1] (see spelling differences) is the visual perceptual property corresponding in humans to the categories called red, yellow, blue, black, etc.
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Gold, also called golden, is a yellowish orange color which is a representation of the color of the element gold.

Golden (web color gold)


Golden

— Color coordinates —

Hex triplet #FFD700
RGBB
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Yellow is the color evoked by light that stimulates both the L and M (long- and medium-wavelength) cone cells of the retina about equally, but does not significantly stimulate the S
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Brown, when used as a general term, is a color which is a dark yellow, orange, or red, of low luminance relative to lighter or white colored objects.[1]

Some pale orange and yellow colors of lower saturation are called light browns.
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Painting, meant literally, is the practice of applying color to a surface (support) such as paper, canvas, wood, glass, lacquer or concrete. However, when used in an artistic sense, the term "painting" means the use of this activity in combination with drawing, composition and
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pigment is a material that changes the color of light it reflects as the result of selective color absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which the material itself emits light.
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Red ochre and yellow ochre (pronounced /'əʊk.ə/, from the Greek ochros, yellow) are pigments made from naturally tinted clay. It has been used worldwide since prehistoric times.
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3, 4, 6
(amphoteric oxide)
Electronegativity 1.83 (Pauling scale)
Ionization energies
(more) 1st: 762.5 kJmol−1
2nd: 1561.9 kJmol−1
3rd: 2957 kJmol−1

Atomic radius 140 pm
Atomic radius (calc.
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2, −1
(neutral oxide)
Electronegativity 3.44 (Pauling scale)
Ionization energies
(more) 1st: 1313.9 kJmol−1
2nd: 3388.3 kJmol−1
3rd: 5300.5 kJmol−1

Atomic radius 60 pm
Atomic radius (calc.
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1, −1
(amphoteric oxide)
Electronegativity 2.20 (Pauling scale) More

Atomic radius 25 pm
Atomic radius (calc.) 53 pm
Covalent radius 37 pm
Van der Waals radius 120 pm
Miscellaneous

Thermal conductivity (300 K) 180.
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2, −1
(neutral oxide)
Electronegativity 3.44 (Pauling scale)
Ionization energies
(more) 1st: 1313.9 kJmol−1
2nd: 3388.3 kJmol−1
3rd: 5300.5 kJmol−1

Atomic radius 60 pm
Atomic radius (calc.
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Hydrate is a term used in inorganic chemistry and organic chemistry to indicate that a substance contains water.

In organic chemistry, a hydrate is a compound formed by the addition of water to a host molecule. Thus ethanol could be considered to be the hydrate of ethylene.
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Ferruginous redirects here. For the bird, see Ferruginous Hawk


Altogether there are sixteen known iron oxides.[1] These compounds are either oxides (Wüstite, Hematite, β-Fe2O3, Maghemite, γ-Fe2O
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Red ochre and yellow ochre (pronounced /'əʊk.ə/, from the Greek ochros, yellow) are pigments made from naturally tinted clay. It has been used worldwide since prehistoric times.
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Goethite, named after the German polymath Johann Wolfgang von Goethe, is an iron bearing oxide mineral found in soil and other low temperature environments. Goethite has been well known since prehistoric times for its use as a pigment.
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Ferruginous redirects here. For the bird, see Ferruginous Hawk


Altogether there are sixteen known iron oxides.[1] These compounds are either oxides (Wüstite, Hematite, β-Fe2O3, Maghemite, γ-Fe2O
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Rust is a general term for iron oxides formed by the reaction of iron with oxygen. Several forms of rust are distinguishable visually and by spectroscopy, and form under different circumstances.
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Motto
none
Anthem
Ύμνος εις την Ελευθερίαν
Imnos is tin Eleftherian
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Commune of
Roussillon

Former ochre quarry in Roussillon

Location
Longitude 05° 17' 37" E
Latitude 43° 54' 11" N

Administration
Country  France
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