Natural ultramarine.

Natural ultramarine painted on paper.

Synthetic ultramarine.

Ultramarine is a blue pigment, consisting essentially of a double silicate of aluminium and sodium with some sulfides or sulfates, and occurring in nature as a proximate component of lapis lazuli. Also known in the past as azzurrum ultramarine, azzurrum transmarinum, azzuro oltramarino, azur d'Acre, pierre d'azur, Lazurstein. Current terminology for ultramarine include natural ultramarine (English), outremer lapis (French), Ultramarin echt (German), oltremare genuino (Italian), and ultramarino verdadero (Spanish). The pigment color code is P. Blue 29 77007. Ultramarine is the most complex of the mineral pigments, a complex sulfur-containing sodio-silicate (Na_8-10Al₆Si₆O₂₄S_2-4), essentially a mineralized limestone containing a blue cubic mineral called lazurite. Some chloride is often present in the crystal lattice as well. The blue color of the pigment is due to the S₃^- radical anion, which contains an unpaired electron. Image of natural Ultramarine pigment, taken by Palladian This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Image of natural Ultramarine pigment, taken by Palladian This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Image of natural Ultramarine pigment, prepared as casein paint and applied to paper, prepared by Palladian This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Image of natural Ultramarine pigment, prepared as casein paint and applied to paper, prepared by Palladian This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... image of synthetic ultramarine, taken by Palladian This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... image of synthetic ultramarine, taken by Palladian This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Blue (from Old High German blao shining) is one of the three primary additive colors; blue light has the shortest wavelength range (about 420-490 nm) of the three primary colors. ... In biology, pigment is any material resulting in color in plant or animal cells which is the result of selective absorption. ... In chemistry, a silicate is a compound consisting of silicon and oxygen (SixOy), one or more metals, and possibly hydrogen. ... General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13 (IIIA), 3, p Density, Hardness 2700 kg/m3, 2. ... General Name, Symbol, Number sodium, Na, 11 Series alkali metal Group, Period, Block 1 (IA), 3, s Density, Hardness 968 kg/m3, 0. ... In chemistry, a sulfide (sulphide in British and Canadian English) is a chemical compound or combination of sulfur with an oxidation number of -2, with another chemical element or a radical thereof. ... Sulfate is the IUPAC name for the SO42- ion, consisting of a central sulfur atom single bonded to four tetrahedrally oriented oxygen atoms. ... A block of lapis lazuli Lapis lazuli is one of the oldest of all gems, with a history of use stretching back 7,000 years. ... Minerals are natural compounds formed through geological processes. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16 (VIA), 3, p Density, Hardness 1960 kg/m3, 2 Appearance Lemon yellow at STP Atomic properties Atomic weight 32. ... General Name, Symbol, Number sodium, Na, 11 Series alkali metal Group, Period, Block 1 (IA), 3, s Density, Hardness 968 kg/m3, 0. ... In chemistry, a silicate is a compound consisting of silicon and oxygen (SixOy), one or more metals, and possibly hydrogen. ... Limey shale overlaid by limestone. ... A block of lapis lazuli Lapis lazuli is one of the oldest of all gems, with a history of use stretching back 7,000 years. ... The chloride ion is formed when the element chlorine picks up one electron to form the anion (negatively charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and are also called chlorides. ... The word radical can have two distinct meanings in chemistry. ... An anion is an ion with negative charge. ... Properties The electron is a subatomic particle. ...

Uses

The first noted use of lapis lazuli as a pigment can be seen in the 6th- and 7th-century AD cave paintings in Afghanistan temples, near the most famous source of the mineral. Lapis lazuli has also been identified in Chinese paintings from the 10th and 11th centuries and in Indian mural paintings from the 11th, 12th, and 17th centuries. Natural ultramarine is the most difficult pigment to grind by hand, and for all except the highest quality of mineral sheer grinding and washing produces only a pale grayish blue powder. At the beginning of the 13th century an improved method came into use, described by the 15th century artist Cennino Cennini. This process consisted of mixing the ground material with melted wax, resins, and oils, wrapping the resulting mass in a cloth, and then kneading it in a dilute lye solution. The blue particles collect at the bottom of the pot, while the impurities and colorless crystals remain in the mass. This process was performed at least three times, with each successive extraction generating a lower quality material. The final extraction, consisting largely of colorless material as well as a few blue particles, brings forth ultramarine ash which is prized as a glaze for its pale blue transparency. Cennino DAndrea Cennini (c. ... Wax has traditionally referred to a substance that is secreted by bees (beeswax) and used by them in constructing their honeycombs. ... Resin is a hydrocarbon secretion formed in special resin canals of many plants, from many of which (for example, coniferous trees) it is exuded in soft drops from wounds, hardening into solid masses in the air. ... Oil is a generic term for organic liquids that are not miscible with water. ... Lye is an alternative name for the chemicals sodium hydroxide (soda lye) or (less commonly) potassium hydroxide (potash lye). ... Painting technique Glaze is a term for painting with a transparent medium. ...

The pigment was most extensively used during the 14th through 15th centuries, as its brilliance complemented the vermilion and gold of illuminated manuscripts and Italian panel paintings. From the beginning of the 16th century this pigment began to be imported into Europe from "over the sea," as azurrum ultramarinum. As lapis lazuli only yields from 2 to 3% of the pigment, it is not surprising to learn that the pigment used to be weighed up with gold. It was valued chiefly on account of its brilliancy of tone and its inertness in opposition to sunlight, oil, and slaked lime. It is, however, extremely susceptible to even minute and dilute mineral acids and acid vapors. Dilute HCl, HNO₃, and H₂SO₄ rapidly destroy the blue color, producing hydrogen sulfide (H₂S) in the process. Acetic acid attacks the pigment at a much slower rate than mineral acids. Because of this susceptibility, ultramarine was only used for frescoes when it was applied "secco", in which the pigment was mixed with a binding medium and applied over dry plaster (such as Giotto di Bondone's frescos in the Cappella degli Scrovegni or Arena Chapel in Padua). Categories: Colors | Pigments | Stub ... General Name, Symbol, Number Gold, Au, 79 Chemical series transition metals Group, Period, Block 11 (IB), 6, d Density, Hardness 19300 kg/m3, 2. ... World map showing location of Europe A satellite composite image of Europe Europe is geologically and geographically a peninsula, forming the westernmost part of Eurasia. ... Oil is a generic term for organic liquids that are not miscible with water. ... Calcium oxide (CaO), commonly known as lime, quicklime or burnt lime, is a widely used chemical compound. ... An acid (often represented by the generic formula AH) is typically a water-soluble, sour-tasting chemical compound. ... For an alternative meaning for H2S, see H2S radar. ... The chemical compound acetic acid (from the Latin word acetum, meaning vinegar), systematically called ethanoic acid, is the acid that gives vinegar its sour taste. ... A XIV Century fresco featuring Saint Sebastian Note: Fresco is the NATO reporting name of the Mikoyan-Gurevich MiG-17. ... Giotto di Bondone (better known as just Giotto, 1267 - January 8, 1337) was an Italian painter and architect. ... The Cappela degli Scrovegni in Padua also known as the Arena Chapel is regarded as one of the masterpieces of Western Art. ... The Cappella degli Scrovegni in Padua (also known as the Arena Chapel) is regarded as one of the masterpieces of Western Art. ... Location within Italy Tronco Maestro Riviera: a pedestrian walk along a section of the inland waterway or naviglio interno of Padua The city of Padua (Lat. ...

European artists used the pigment sparingly, reserving their highest quality blues for the robes of Mary and the Christ child. As a result of the high price, artists sometimes economized by using a cheaper blue, azurite, for under painting. Most likely imported to Europe through Venice, Italy, the pigment was seldom seen in German art or art from countries north of Italy. Due to a shortage of azurite in the late 16th and 17th century the demand for the already-expensive ultramarine increased dramatically. In 1814 Tassaert observed the spontaneous formation of a blue compound, very similar to ultramarine, if not identical with it, in a lime kiln at St. Gobain, which caused the Societé pour l'Encouragement d'Industrie to offer, in 1824, a prize for the artificial production of the precious colour. Processes were devised by Jean Baptiste Guimet (1826) and by Christian Gmelin (1828), then professor of chemistry in Tubingen; but while Guimet kept his process a secret Gmelin published his, and thus became the originator of the "artificial ultramarine" industry. Categories: Mineral stubs | Carbonate minerals | Pigments ... 1814 was a common year starting on Saturday (see link for calendar). ... Calcium oxide (CaO), commonly known as lime, quicklime or burnt lime, is a widely used chemical compound. ... Charcoal Kilns, California A kiln is an oven that is used for hardening, burning, or drying anything. ... 1824 was a leap year starting on Thursday (see link for calendar). ... 1826 was a common year starting on Sunday (see link for calendar). ... Christian Gottlob Gmelin (October 12, 1792 _ May 13, 1860) was a German chemist. ... 1828 was a leap year starting on Tuesday (see link for calendar). ...

Chemistry and manufacture

The raw materials used in the manufacture are: (1) iron-free kaolin, or some other kind of pure clay, which should contain its silica and alumina as nearly as possible in the proportion of SiO₂:Al₂O₂ demanded by the formula assigned to ideal kaolin (a deficit of silica, however, it appears can be made up for by addition of the calculated weight of finely divided silica); (2) anhydrous sulfate of soda; (3) anhydrous carbonate of soda; (4) sulfur (in the state of powder); and (5) powdered charcoal or relatively ash-free coal, or colophony in lumps. "Ultramarine poor in silica" is obtained by fusing a mixture of soft clay, sodium sulfate, charcoal, soda and sulfur. The product is at first white, but soon turns green ("green ultramarine") when it is mixed with sulfur and heated. The sulfur fires, and a fine blue pigment is obtained. "Ultramarine rich in silica" is generally obtained by heating a mixture of pure clay, very fine white sand, sulfur and charcoal in a muffle-furnace. A blue product is obtained at once, but a red tinge often results. The different ultramarines—green, blue, red and violet—are finely ground and washed with water. General Name, Symbol, Number iron, Fe, 26 Chemical series transition metal Group, Period, Block 8 (VIIIB), 4, d Density, Hardness 7874 kg/m3, 4. ... Kaolin Kaolinite (Aluminium Silicate Hydroxide) Kaolinite is a mineral with the chemical composition Al2Si2O5(OH)4. ... Clay is a generic term for an aggregate of hydrous silicate particles less than 4 μm (micrometres) in diameter. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... Aluminium oxide (or aluminum oxide) (Al2O3) is a chemical compound of aluminium and oxygen. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16 (VIA), 3, p Density, Hardness 1960 kg/m3, 2 Appearance Lemon yellow at STP Atomic properties Atomic weight 32. ... Charcoal is the blackish residue consisting of impure carbon obtained by removing water and other volatile constituents of animal and vegetable substances. ... Coal is a fossil fuel extracted from the ground either by underground mining, open-pit mining or strip mining. ... Rosin is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vapourise the volatile liquid terpene components. ... Glaubers salt, also sal mirabilis, is the name of sodium sulfate decahydrate, Na2SO4•10H2O, which was discovered by and named for the 17th-century German iatrochemist Johann Glauber. ... Patterns in the sand Sand is an example of a class of materials called granular matter. ...

Synthetic alternatives

Synthetic ultramarine is not as vivid a blue as natural ultramarine, since the particles in synthetic ultramarine are smaller and more uniform than natural ultramarine and therefore diffuse light more evenly. Synthetic ultramarine is also not as permanent as natural ultramarine. Diffusion is the spontaneous spreading of something such as particles, heat, or momentum. ...

Artificial, like natural, ultramarine has a magnificent blue colour, which is not affected by light nor by contact with oil or lime as used in painting. Hydrochloric acid immediately bleaches it with liberation of hydrogen sulfide. It is remarkable that even a small addition of zinc-white (oxide of zinc) to the reddish varieties especially causes a considerable diminution in the intensity of the colour, while dilution with artificial precipitated sulfate of lime ("annalin") or sulfate of baryta ("blanc fix") acts pretty much as one would expect. Ultramarine being very cheap, it is largely used for wall painting, the printing of paperhangings and calico, etc., and also as a corrective for the yellowish tinge often present in things meant to be white, such as linen, paper, etc. Bluing or "Laundry blue" is a solution of synthetic ultramarine that is used for this purpose when washing white clothes. Large quantities are used in the manufacture of paper, and especially for producing a kind of pale blue writing paper which is popular in Britain. The chemical substance hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl) gas. ... General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Density, Hardness 7140 kg/m3, 2. ... Torn linen cloth, recovered from the Dead Sea Linen is a material made from the fibers of the flax plant. ... Piece of paper Paper is a thin, flat material produced by the compression of fibres. ...

By treating blue ultramarine with silver nitrate solution, "silver-ultramarine" is obtained as a yellow powder. This compound gives a blue potassium- and lithium-ultramarine when treated with the corresponding chloride, and an ethyl-ultramarine when treated with ethyl iodide. Selenium- and tellurium-ultramarine, in which these elements replace the sulfur, have also been prepared. Silver nitrate is a chemical compound with chemical formula AgNO3. ... General Name, Symbol, Number potassium, K, 19 Series alkali metals Group, Period, Block 1(IA), 4, s Density, Hardness 856 kg/m3, 0. ... General Name, Symbol, Number Lithium, Li, 3 Series Alkali metal Group, Period, Block 1(IA), 2, s Density, Hardness 535 kg/m3, 0. ... The chloride ion is formed when the element chlorine picks up one electron to form the anion (negatively charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and are also called chlorides. ... Ethyl is a two-carbon substituent in organic chemistry. ... Definition An iodide ion is an iodine atom with charge -1. ... General Name, Symbol, Number selenium, Se, 34 Series nonmetals Group, Period, Block 16 (VIA), 4, p Density, Hardness 4790 kg/m3(300K), 2 Appearance grey, metallic lustre Atomic properties Atomic weight 78. ... General Name, Symbol, Number tellurium, Te, 52 Series metalloids Group, Period, Block 16 (VIA), 5, p Density, Hardness 6240 kg/m3, 2. ...

External links

• "Discussion of Ultramarine in an article on blue pigments in early Sienese paintings from The Journal of the American Institute for Conservation" (http://aic.stanford.edu/jaic/articles/jaic30-02-001.html)

This article incorporates text from the public domain 1911 Encyclopædia Britannica. The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ... The Eleventh Edition of the Encyclopædia Britannica (1911) in many ways represents the sum of knowledge at the beginning of the 20th century. ...