Editing Violet (color) (section)

==In science==

===Optics===
[[File:Linear visible spectrum.svg|center|400px]]
Violet is at one end of the [[Visible spectrum|spectrum of visible light]], between [[blue]] light, which has a longer wavelength, and [[ultraviolet]] light, which has a shorter wavelength and is not visible to humans. Violet wavelengths are between approximately 380 and 435 nanometers. The color violet appears dark because the S cones, which contribute very little to the perception of lightness, do not have a high sensitivity to violet light. The reason why to (typical [[trichromacy|trichromat]]) humans violet light appears slightly reddish compared to spectral blue (despite spectral red being at the other end of the visible spectrum) is, according to the [[opponent process|opponent process hypothesis of color vision]], that the S-[[cone cell|cone]] type (i.e. the one most sensitive to short wavelengths) contributes some red to the red-versus-green opponent channel (which at the longer blue wavelengths gets counteracted by the M-cone type).<ref name="Machado2009">{{citation | last1 = Machado | first1 = G.M. | last2 = Oliveira | first2 = M.M. | last3 = Fernandes | first3 = L. | title = A Physiologically-based Model for Simulation of Color Vision Deficiency | journal = IEEE Transactions on Visualization and Computer Graphics | publisher = Institute of Electrical and Electronics Engineers (IEEE) | date = November 2009 | volume = 15 | issue = 6 | pages = 1291–1298 | issn = 1077-2626 | doi = 10.1109/TVCG.2009.113 | pmid = 19834201 | hdl = 10183/27630 | s2cid = 6200253 | url = https://www.inf.ufrgs.br/~oliveira/pubs_files/CVD_Simulation/CVD_Simulation.html| hdl-access = free }} Figure 2 shows S-cones contributing +0.40 to the "r − g" opponent channel.</ref> Computer and television screens, using the [[RGB color model]], cannot produce spectral violet light and instead they combine blue light at high intensity with red light at less intensity.

Monochromatic lamps emitting spectral-violet wavelengths can be roughly approximated by the color named electric violet, which is a composed-light violet producing a similar effect to the human eye.{{Citation needed|date=September 2023}}

===Chemistry – pigments and dyes===
The earliest violet pigments used by humans, found in prehistoric cave paintings, were made from the minerals [[manganese]] and [[hematite]]. Manganese is still used today by the [[Aranda people]], a group of [[indigenous Australians]], as a traditional pigment for coloring the skin during rituals. It is also used by the [[Hopi]] Indians of [[Arizona]] to color ritual objects.

The most famous violet-purple dye in the ancient world was [[Tyrian purple]], made from a type of sea snail called the [[murex]], found around the Mediterranean.

In western [[Polynesia]], residents of the islands made a violet dye similar to Tyrian purple from the [[sea urchin]]. In Central America, the inhabitants made a dye from a different sea snail, the [[Purpura (gastropod)|purpura]], found on the coasts of [[Costa Rica]] and [[Nicaragua]]. The Mayans used this color to dye fabric for religious ceremonies, and the Aztecs used it for paintings of ideograms, where it symbolized royalty.<ref name="Anne Carichon 2000 p. 1332">Anne Carichon (2000), ''Couleurs: pigments et teintures dans les mains des peuples''. p. 133</ref>

During the Middle Ages, most artists made purple or violet on their paintings by combining red and blue pigments; usually blue azurite or lapis-lazuli with [[red ochre]], [[cinnabar]] or [[Minium (pigment)|minium]]. They also combined lake colors by mixing dye with powder; [[woad]] or [[indigo]] dye for blue and [[cochineal]] dye for red.<ref name="Anne Carichon 2000 p. 1332" />

[[Orcein]], or ''purple moss'', was another common violet dye. It was known to the ancient Greeks and Hebrews, was made from a Mediterranean [[lichen]] called archil or dyer's moss ([[Roccella tinctoria]]), combined with an [[ammoniac]], usually urine. Orcein began to achieve popularity again in the 19th century, when violet and purple became the color of demi-mourning, worn after a widow or widower had worn black for a certain time, before he or she returned to wearing ordinary colors.<ref>Anne Carichon (2000), ''Couleurs: pigments et teintures dans les mains des peuples''. p. 144</ref>

In the 18th century, chemists in England, France and Germany began to create the first synthetic dyes. Two synthetic purple dyes were invented at about the same time. '''Cudbear''' is a [[dye]] extracted from [[orchil]] [[lichen]]s that can be used to dye [[wool]] and [[silk]], without the use of [[mordant]]. Cudbear was developed by Cuthbert Gordon of [[Scotland]]: production began in 1758, The lichen is first boiled in a solution of [[ammonium carbonate]]. The mixture is then cooled and [[ammonia]] is added and the mixture is kept damp for 3–4 weeks. Then the lichen is dried and ground to powder. The manufacture details were carefully protected, with a ten-foot high wall built around the manufacturing facility, and staff consisting of Highlanders sworn to secrecy.

'''French purple''' was developed in France at about the same time. The lichen is extracted by urine or ammonia. Then the extract is acidified, the dissolved dye precipitates and is washed. Then it is dissolved in ammonia again, the solution is heated in air until it becomes purple, then it is precipitated with [[calcium chloride]]; the resulting dye was more solid and stable than other purples.

'''[[Cobalt violet]]''' is a synthetic pigment that was invented in the second half of the 19th century, and is made by a similar process as [[cobalt blue]], [[cerulean blue]] and [[cobalt green]]. It is the violet pigment most commonly used today by artists, along with [[manganese violet]].

'''[[Mauveine]]''', also known as '''[[aniline]] [[purple]]''' and '''Perkin's [[mauve]]''', was the first synthetic [[organic chemistry|organic chemical]] dye,<ref>{{Cite journal|author=Hubner K|year=2006|title=History – 150 Years of mauveine|journal=Chemie in unserer Zeit|volume=40|issue=4|pages=274–275|doi=10.1002/ciuz.200690054}}</ref><ref>{{Cite journal|author=Anthony S. Travis|year=1990|title=Perkin's Mauve: Ancestor of the Organic Chemical Industry|journal=Technology and Culture|volume=31|issue=1|pages=51–82|doi=10.2307/3105760|jstor=3105760|s2cid=112031120 }}</ref> discovered [[serendipity|serendipitously]] during an attempt to make quinine in 1856. Its chemical name is 3-amino-2,±9-dimethyl-5-phenyl-7-(p-tolylamino) phenazinium acetate.

In the 1950s, a new family of violet synthetic organic pigments called [[quinacridone]]s came onto the market. They had originally been discovered in 1896, synthesized in 1936 and manufactured in the 1950s. The colors in the group range from deep red to violet in color, and have the molecular formula C<sub>20</sub>H<sub>12</sub>N<sub>2</sub>O<sub>2</sub>. They have strong resistance to sunlight and washing, and are used in oil paints, watercolors and acrylics, as well as in automobile coatings and other industrial coatings.<gallery mode="packed" heights="220">
File:Amatista Laye 2.jpg|In [[amethyst]], the violet color arises from an impurity of iron in the quartz.
File:Pigment Violet 29.svg|Chemical structure of [[Pigment Violet 29|pigment violet 29]]. Violet pigments typically have several rings.
File:Manganese violet.jpg|Manganese violet, a popular inorganic pigment.
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===Zoology===
<gallery heights="220" mode="packed">
File:Messina Straits Argyropelecus hemigymnus.jpg|The [[marine hatchetfish]] (here eating a small crustacean) lives in extreme depths.
File:PurpleUrchinPuertoVG.JPG|The [[Strongylocentrotus purpuratus|purple sea urchin]].
File:Xylocopa violacea-Abeille charpentière-201606102.jpg|The violet carpenter bee ([[Xylocopa violacea]]) is one of the largest bees in [[Europe]].
File:Cinnyricinclus leucogaster - 20080321.jpg|The [[violet-backed starling]] is found in [[Sub-Saharan Africa]].
File:Violet Sabrewing JCB.jpg|The [[violet sabrewing]] is found in [[Central America]].
File:Amazona imperialis -Roseau -Dominica -aviary-6a-3c.jpg|The [[imperial amazon]] parrot is featured on the national flag of [[Dominica]], making it the only national flag in the world with a violet color.
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===Botany===
<gallery heights="200" mode="packed">
File:Lobelia (aka).jpg|[[Lobelia]]
File:- Crocus -.jpg|[[Crocus]] flowers.
File:Royal Botanical Gardens Lilac Celebration.JPG|[[Lilac]] flowers
File:Pensées violettes et noires.JPG|[[Pansy]] flowers.
File:Viole.jpg|[[Sweet Violet|Sweet violet]] flowers.
File:Iris sanguinea 2007-05-13 361.jpg|The [[iris (plant)|iris]] flower takes its name from the [[Greek language|Greek]] word for [[rainbow]].
File:Vaucluse lavanda.jpg|[[Lavender]] fields in the [[Vaucluse]], in [[Provence]], France
File:Glycine (Wisteria) (2).jpg|alt=Wisteria blooms are a light violet color.|[[Wisteria]] blooms are a light violet color.
File:Aubergine.jpg|An [[eggplant]].
</gallery>