Optics Violet is at one end of the
spectrum of visible light, between
indigo 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
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 hypothesis of color vision, that the S-
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). 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.
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, 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. 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. They also combined lake colors by mixing dye with powder;
woad or
indigo dye for blue and
cochineal dye for red. 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 lichens 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 chemical dye, discovered
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
quinacridones 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 C20H12N2O2. 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. 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. Violet pigments typically have several rings. File:Manganese violet.jpg|Manganese violet, a popular inorganic pigment.
Zoology File:Messina Straits Argyropelecus hemigymnus.jpg|The
marine hatchetfish (here eating a small crustacean) lives in extreme depths. File:PurpleUrchinPuertoVG.JPG|The
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.
Botany 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 flowers. File:Iris sanguinea 2007-05-13 361.jpg|The
iris flower takes its name from the
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. ==In history and art==