Written before translation: Many pigments in history have been taken from gem materials, such as hematite, azurite, malachite, etc., of which the use of hematite can be traced back to the caveman period, is one of the oldest pigments used, malachite can be traced back to 6,000 years ago in Egyptian cosmetics. Through historical combing, the use of pigments is often accompanied by the rise of major art movements, each of which will lead to a fundamental shift in art history. Britni LeCroy of Gemology at GIA's Carlsbad Laboratory recently published an article in Gems & Gemology titled "Gems on Canvas: Pigments Historically Sourced from Gem Materials," which systematically summarizes the history of gem minerals used in pigments.
1. Overview
In ancient times, wearing jewelry was mainly used to highlight the status and charm of its owner, because the value of gemstones is relatively high, research methods are mainly non-destructive testing, the research content mainly includes the source characteristics of gemstones, artificial synthesis and gemstone optimization. For gemologists, destroying gemstones is a felony, but in the field of pigments, gemstones collide with mortars and pestles to form pigments, which are equally immortalized in canvases, murals, cave paintings, and as a form of recording, it transcends any written or spoken language. In the early days, people usually used hematite, azurite, lapis lazuli, bone, ivory, cinnabar, etc. as pigments, which are of great significance in the history of pigments. Color research is a very important cross-cutting field, involving geology, art, anthropology, history, and even gemology, and professionals in various fields have contributed their knowledge to this field.
Figure 2 Gem materials and corresponding pigments
Natural inorganic pigments are generally derived from natural rocks or minerals, while synthetic materials have the same chemical properties as natural pigments. However, because the synthetic material strives for high purity and high uniformity, and the natural pigment is not uniform due to the complexity of the formation environment, the natural material in the processed particle size and structure of the tiny defects give the color a unique fingerprint character, this personalized hue, so that the way of reflecting light is more complex than the corresponding synthetic pigment, which means that no two malachite green and cinnabar red are exactly the same. When applied to the canvas, the natural color pigment provides a more natural sense with a tiny gritty texture that can be seen and felt after drying.
The binder is the second most important component of the pigment, which plays the role of fixing the pigment and keeping the color of the pigment unchanged after drying. Historically, binders have been mainly natural substances such as egg yolk, flaxseed oil, poppy seed oil, resin, saliva, milk, gelatin, and even blood. Today, acrylic pigments are synthetic chemical binders, but flaxseed oil and gum arabic, a hardened resin, are still widely used.
Pigments have been studied for centuries, which has helped to deepen people's understanding of science and art. Determining the mineral origin of the pigments in a work helps to study important information about the trade routes and human movements of the work at the time of its creation. The development of pigment technology, including advances in chemical and industrial technology, can also be judged by the contrast between earlier cave paintings and acrylic paintings in museums. The former consists of natural pigments such as ochre (derived from iron oxides) charcoal and simple organic pigments, whereas today's paintings are usually all artificially made pigments.
The advent of cheap, mass-produced pigments was the culmination of research hundreds of years ago, but before this revolutionary invention, making pigments was expensive and laborious, each pigment had to be handled by hand by artists or their assistants, and minerals used for pigments often needed to be transported long distances to reach these artists, which also increased the cost of pigments. The painting itself was reserved for those who could afford to enjoy these luxuries, or those lucky enough to be employed by royalty, the rich or churches. This is why most history paintings are religious or royal or aristocratic portraits.
A relatively new field of application in the study of pigments is in art conservation and art restoration. This is not so much an art as a science, jewelry needs to go through various tests, including visible light spectrum, Raman spectroscopy, infrared spectroscopy, and ultraviolet fluorescence, X-ray fluorescence, etc., these test methods are very common in gemological laboratories, first of all, ultraviolet fluorescence can determine the presence of organic materials and varnishes, X-ray fluorescence can obtain information on the composition of elements, infrared spectroscopy can find areas of loss of original primer and paint, Raman spectroscopy is mainly used to identify the mineral composition in pigments.
Figure A-1. Raman spectroscopy analyzes Raphael's School of Athens
Among these tests, the real magic is the visible light spectrum, which can interpret the visible light spectrum produced by the pigments, and by building a database to match the spectra with known pigments, more accurate reproductions of pigments can be used during the restoration process, ensuring that important works of art remain properly constructed for future generations to enjoy.
The overlap between gemology and art is not very common. The monetary and cultural significance of a gemstone may be far less than its contribution as a pigment to the value of a work of art. Throughout history, hematite, azurite, malachite, lapis lazuli, bone, ivory, and cinnabar have been important contributors to art, most of which have been replaced by synthetic pigments, but some are still in use today (Figure 2).
2. Hematite
Hematite is one of the gem minerals known to act as pigments yesterday morning, gem-quality hematite has a darker metallic color, mainly associated with dense stacking of dark red crystallites, absorbing most of the visible light in the spectrum, and when hematite is present in the form of powdered or light-transmitting thin crystals, its color is red. Hematite is one of the few gemstones with a metallic luster, a trigonal crystal system with an extremely simple chemical formula, Fe2O3. Its most popular era as a gemstone is probably the Victorian era, when it was often used to mourn jewelry.
Figure 3 Hematite crystals in quartz, field of view 7.22mm
In the field of art, powdered hematite, known as red ochre, began to be used at the beginning of artistic expression. Red ochre can also be obtained by heating goethite or limonite. From the time of renewal to the present day, the use of red ochre as a pigment has been documented in works of art from all periods and traditions around the world. The first use of red ochre was probably in cave paintings and body painting. Later used in burial or fertility ceremonies to represent blood, red ochre was also used in sunscreen, medicine, binders and ceramic coatings.
Figure 4 Early cave paintings painted using red ochre in the Lascaux caves.
Figure 5 The entrance to the Cueva de las Manos (cave of hands) shows a red ochre handprint created by members of ancient Argentine tribes
The effect of red ochre on pigments is unmatched by other pigments. From the time of prehistoric art (before 500 BC) to contemporary times, red ochre is everywhere. The earliest cave paintings from every habitable continent on Earth show the most primitive artistic abilities of mankind, and all feature red ochre. A well-known case study is the French Lascaux cave art, dating back to 19,000 years ago, and the mural depicts wild animals such as bison and horses (Figure 4). Another younger example is the Cueva de las Manos (Cave of the Hand) in Argentina, created 13,000–9,500 years ago, in which hand-drawn outlines of hands are shown (Figure 5). Scholars generally agree that the use of red ochre as a pigment is synonymous with the origins of art. In fact, the use of red ochre and tool-making are two major advances in human evolution, the latter of which is widely recognized as an important indicator of human intellectual, social and cultural development. Theoretically, the combination of art and science began with the use of red ochre.
The Blombus Cave archaeological site on the Cape coast of South Africa is a major anthropological discovery related to red ochre, which does not exist in one form, but in abalone shells, which were abandoned on cave floors for thousands of years and slowly buried by sand. Other materials found along with shells and ochre include pebbles, seals and antelope bones, and some stone tools, thought to be a prehistoric art toolbox from 100,000 years ago. These findings tell us that the artisans who lived here 100,000 years ago already had abstract thinking, multitasking skills, long-term planning skills, and basic knowledge of chemistry.
To this day, cave paintings are still considered one of Homo sapiens unique features, and in 2018, a team of paleoanthropologists published U-Th dating data for a series of simple drawings found in three Spanish caves. The points, lines, discs and handmade stencils examined in the study, all made of red ochre, are at least 64,000 years old, at least 20,000 years before humans arrived in Europe. Neanderthals at the time only lived in modern Europe, which also means that these artists were indeed Neanderthals, and their ability to create art helped dispel the common misconception that Neanderthals were intellectually inferior to Homo sapiens.
Figure 6 Elisha Kokar's pastel-colored (chalk-painted red ochre) prints from the early 18th century
Every artist in history who has been enshrined as a saint has used red ochre at some point. This color is also a traditional ingredient in red chalk. Leonardo da Vinci loved the material and used the color in many paintings of the Renaissance, while da Vinci is considered one of the first artists to use this red ochre, Michelangelo continued to use this ochre, and the use of red ochre in frescoes was equally popularized during this period. Paul Gauguin, one of the most famous painters of the Post-Impressionist movement, made this color the main element of his palette. The importance of red ochre to modern art is immeasurable. 20th-century masters such as Pablo Picasso, Mark Rothko and Andy Warhol all created works featuring this color, bringing it back to square one. While most natural pigments have been far surpassed by synthetic pigments, red ochre is an exception, mainly because red ochre is mainly derived from natural hematite or heated goethite, which is abundant and inexpensive.
3. Azurite and malachite
Malachite is a bright green pigment belonging to the basic carbonate of copper, weathered by blue azurite, and the two have a similar chemical formula. Azurite and malachite rarely exist alone, but occur mostly in copper oxide zones. Both minerals are monoclinic and have a low hardness of 3.5-4.0 on the Mohs scale. Malachite has been widely used in decoration since ancient times, but azurite has greatly limited its decorative use due to its lower durability and deconditioning, and is mainly used as a pigment.
The earliest possible applications of azurite and malachite were in cosmetics, with malachite dating back to ancient Egypt, the pre-dynastic period between 6000 BC and 3100 BC, and was mainly used as an eye pigment. Similarly, the application of high-purity, coarsely ground azurite dates back to the burials of women and babies at the 6,700-year-old Neolithic site of Anatolia (present-day Turkey), where the mineral may also have been used as a cosmetic material. Since 4500 BC, these two minerals have been used in the Middle East to color soapstone.
Figure 7 The Martyrdom of St. Lawrence by Pacino di Bonagueda, by Laudario of Sant'Agnese (circa 1340)
Figure 8 Ogata Kõrin's Iris of the Eight Bridges, early 18th century. These famous screens feature flat malachite green and navy on gold foil.
Although azurite reserves are nowhere near as high as malachite, azurite is more widely used as a pigment. Throughout the Middle Ages, it was the most important pigment in Europe, reaching its peak during the Renaissance. This is mainly related to its dual role, which is not just the color of royalty, but also the primer of luxurious deep blue (lapis lazuli), two pigments used in Japan for hundreds of years, such as ukiyo-e (16th to 19th centuries), and malachite is still used in screens and scroll paintings today. These two pigments have also been widely used in Chinese historical art for hundreds of years.
Copper and copper-bearing metals are most often associated with patina with a bright green color. Chinese history reveals the ingenious application of malachite in imitating patina. Beginning around 1000 AD, patina began to be associated with ancient bronzes unearthed in China, a feature sought after by collectors of antique bronzes, giving a sense of authenticity. Bronze statues unearthed from the Song, Ming and Qing dynasties were often painted with malachite pigment on replicas to achieve the effect of imitating patina. Blue azurite is not universal, but it can still occur under certain conditions.
Figure 9 Renoir's Chrysanthemum (1881-1882, oil on canvas), using green malachite pigments, is a fine example of the Impressionist style
Malachite was of great importance in European shelf painting from the 14th to the 17th centuries, until the advent of patina (such as patina and copper resin), when synthetic green pigments replaced malachite around 1800, and experienced a brief revival in the 19th century, it was during this period that Pierre-Auguste Renoir created the work Chrysanthemum (fig. 9). Renoir, along with his contemporaries Monet, Cézanne, Degas and Manet, helped consolidate the Impressionist movement. Impressionism is characterized by short, thick brushstrokes creating spontaneous unfinished looks, vibrant color palettes and natural themes. The movement was supported by ready-made precast tubing oil paints, which brought unprecedented fluidity and avant-garde artists could take their work outdoors. The movement flourished from the mid-to-late 19th century and had the most significant influence on modern art.
Figure 10. Malachite (left) and azurite (right) show different saturations due to different particle sizes
Since the color of malachite and azurite depends on the size of the grain, which limits them as pigments (Figure 10), the fine abrasive material provides a better texture for the canvas but reduces the saturation of the color. Coarser grains provide higher saturation colors, but are difficult to draw. With the invention of the artificial pigment Prussian blue, azurite was gradually phased out in the 19th century.
4. Lapis lazuli
Lapis lazuli is a complex metamorphic rock composed of a variety of minerals such as calcite and pyrite, and the blue origin of lapis lazuli is still a problem to be solved, but it is generally believed to be related to blue ashlar (haüyne), which along with sodalite and zoifernite belong to the sodalite group. Some studies have shown that blue ashlar predominates over lapis lazuli from Sar-e-Sang in Afghanistan and Baffin Island in Canada. In addition, samples from the Coquimbo region of Chile are mainly lapis lazuli.
Of the natural pigments in history, the deep blue color extracted from lapis lazuli is the most prized. Cennino Cennin was a 15th-century Italian painter and author of The Handbook of Artisans (1437), an artist's manual on methods and techniques that remains of great importance today. Cennini highly regarded the pigment, describing it as "Ultramarine blue as an outstanding, beautiful, and perfect color that transcends all colors." In its heyday, blue was a sacred color, used only in the most important works and the most sacred religious figures. The deep blue was said to be as expensive as gold of the same weight at the time, and the high cost stemmed from having only one source and the complex procedures required to process it into pure pigments. The history of lapis lazuli as a pigment can be traced back to the origins of human civilization itself.
Blue is the most abundant color in nature, such as the sky, the ocean, but in fact, these colors do not only contain blue light, for example, the blue of the sky is the result of the scattering of light by atmospheric molecules, the blue of the sea because it preferentially absorbs red light, but the causes of these two blues are related to the physical action of light, and only a few plants and animals have real blue pigments, which leaves very few choices for artists in history. From the Middle Ages to the Renaissance, azurite predominated, but it had a typical green undertone that could not be removed, limiting its application, in contrast to the deep blue lapis lazuli containing violet-purplish undertones (Figure 2), thus creating this vivid color, which was later associated with the gods.
Figure 11 Left: A miner at the Sar-e-Sang lapis lazuli mine in Afghanistan. Right: Blue lapis lazuli veins contrast to carbonate host rocks.
Due to its scarcity of origin, ancient lapis lazuli was only produced at the Sar-e-Sang mine in the Badakhshan Mountains in northeastern Afghanistan, which began in the Stone Age and has now found jewelry made of lapis lazuli in the tombs of the Mehrgarh people (Neolithic settlements in present-day southwestern Pakistan), dating back to 7000 BC.
Lapis lazuli was exported to the ancient Sumerian civilization of Mesopotamia about 3,000 years ago, reached Egypt in pre-dynastic times, and became popular during the First Dynasty. The Egyptians used lapis lazuli in jewelry, setting, medicine, and cosmetics. The most famous artifact of ancient Egypt is the funeral mask of Pharaoh Tutankhamun, inlaid with obsidian, quartz, lapis lazuli, turquoise, amazonite, carnelian and other gemstones, which has become a major feature of this artifact. Part of the inlay uses lapis lazuli as Tutankhamun's eyeliner, representing the elite's use of it as a cosmetic pigment.
Figure 12 George Trupert's Hour (1480-1490), which combines tempera, gold leaf, ink and metallic pigments on parchment
The earliest discovery of dark blue is an oil painting on the wall of the Bamiyan cave in Afghanistan, probably created in the late 6th century with Buddhist motifs in the half-Indian, half-Persian style, and notably, the discovery also reveals the earliest known use of oil as a binder. Dark blue appeared in Europe in the early Middle Ages and became popular in the 14th and mid-15th centuries, when it was heavily used in panel paintings and hand-painted books. In paintings of the 14th and 16th centuries, the highest quality dark blue was preserved on the cloaks of Christ and the Virgin Mary (fig. 12), and dark blue was the most expensive pigment in its heyday, which meant that it was used in very small quantities.
Figure 13. Sasophirato's Madonna in Prayer (1640–50), the blue curtain of the arms of the Virgin Mary is the most vivid example of the deep blue color of classical art
Fig. 14 Johannes Vermeer's most famous painting "The Girl with a Pearl Earring" (circa 1665, oil on canvas)
The widespread publication of pigment extraction processes from lapis lazuli has enhanced the popularity of this deep blue color, and since lapis lazuli is a rock containing a variety of minerals such as calcite and pyrite, it is clearly not enough to prepare lapis lazuli using simple grinding, washing, and sieving alone. If other minerals are not extracted, especially pyrite, this deep blue color will be darkened or even discolored, so the production of this pigment needs to be de-crushed, and high-quality lapis lazuli is screened, and then the powder is formed into a ball with various waxes, kneaded in an alkaline solution, the blue particles slowly precipitate from it into the solution, while heavier substances such as pyrite are retained, and once the liquid evaporates, only the dark blue pigment is left, which may take months or more, which is another factor that contributes to its higher cost. In the following centuries, deep blue gained unparalleled prestige in Europe, and works featuring this color gained eternal fame (Figures 13 and 14).
Figure 15 Titian's Bacchus and Ariadne (1523), depicting a meeting of a Greek mythological figure.
Although dark blue is most often found in Christian artwork, it is also sometimes used to create picturesque skies on canvas. The features of the sky mimic lapis lazuli, and pyrite and calcite shimmering in deep blue resemble stars and clouds. This characteristic is evident in Titian's Bacchus and Ariadne (fig. 15), which also includes azurite, malachite and cinnabar.
In 1824, the French National Industrial Encouragement Association held a competition to synthesize artificial dark blue with a prize of 6,000 francs, and four years later, a method was discovered and Jean Baptiste Guimet became the winner. Known as the "French deep blue," the synthetic material sold for about one-tenth of the natural material and was produced throughout Europe in the mid-19th century, quickly surpassing natural pigments and still doing so today.
5. Bones and ivory
Historically, bone and ivory were often used to make black pigments, and the composition of bone and ivory is more complex, consisting of organic and inorganic substances. Recent studies have identified the inorganic component as hydroxyapatite. When bone or ivory is heated under hypoxic conditions, black pigments are produced, and the carbon source is mainly collagen, which is mainly found in the matrix of the material.
Bone is one of the oldest known gem materials. Recently, archaeologists discovered a nose ring made of bone at sites in Western Australia that is more than 46,000 years old, making it the oldest bone tool found on the continent. Ebonex, the largest producer of bone black pigment in the United States, clearly states that carbonized bovine bone is its main raw material.
Figure 16 Ivory carving, circa 1390-1352 BC, bearing the name "Amenhotep III", the ninth pharaoh of the 18th dynasty of Egypt
Figure 17 "Pictorial Realism of Footballers: Color Clusters in the Fourth Dimension" (1915), featuring ivory black, artificial dark blue and vermilion
Bone blacks have been found in prehistoric, Egyptian, Greek, Roman, medieval and Renaissance art. Light microscopy shows that from the third to second centuries, bone blacks were mainly used on tombstones in ancient Greece. Between the 15th and 20th centuries, ivory and bone black have been scientifically identified in Western European art, including works by Tintoretto, Rubens, Rembrandt, Manet and Renoir. An analysis of works from the Museum of Pablo Picasso in Paris revealed that all 62 paintings contained ivory and bone black. Modern artist Kazimir Malevich, founder of the Supremacist movement, promoted and popularized abstract art with Picasso, whose signature geometric style features ivory black (fig. 17).
The production of white pigments from bone can be carried out under oxidizing conditions. Bone white, which is basically the ash left behind after the destruction of all organic matter, was first used in the Neolithic period, mainly as a paper preparation in metal point drawings. In this technique, a soft metal writing instrument (silver, gold, or copper) is rubbed over a primered paper, usually with a bone-white pigment mixed with rabbit skin glue. The ashes have a slightly abrasive nature that causes the metal to fall off and adhere to the primer surface, similar to the effect of modern graphite pencils on paper. As graphite became easier to use and eventually became more popular, metal dot painting gradually faded from view. Although ashes have little use as a modern pigment, bone black is still sold in art stores.
6. Cinnabar
Cinnabar is a brightly colored mercury sulfide mineral that is the main ore mineral of Hg. It is not very distributed in the earth's crust, only a small number of deposits are found in Europe, the Middle East and Asia, mostly in block structures, and rarely gem-quality single crystals. Its hue is a vivid red with intense orange tinges. The color of cinnabar comes from a simple source, and the pigment can be made by crushing or grinding the mineral in a mortar. A synthetic form commonly known as vermilion, which has existed for centuries is a combination of Hg and S. After the deep blue, cinnabar became the most valuable and prestigious pigment in history, with Spain and China being the main sources of this pigment.
Figure 18. The Macedonian queen or princess plays gilded zitters next to her daughter or sister. The background is characterized by a large display of expensive cinnabar pigments
The area where cinnabar was first used as a pigment was Çatalhöyük in the Middle East, an early human settlement between 7100 BC and 5700 BC, where cinnabar is found in both paintings and tomb backgrounds. Israel's more than 800 Dead Sea scrolls are the world's earliest biblical manuscripts, 4 of which are shown to contain red ink composed of cinnabar. The ancient Romans were obsessed with the use of this pigment in frescoes and gave it great importance and sacred association (fig. 18), pure cinnabar blackened in light conditions, which prompted the Roman scholars Vitruvius and Pliny the Elder to use oil or wax coatings in their work, and recent studies have shown that this discoloration is actually related to cinnabar exposure to halogens or substances containing trace amounts of Cl.
Cinnabar also had a wide cultural spread in China, and during the Shang and Zhou dynasties, cinnabar powder was sprinkled in tombs to preserve the dead. Cinnabar is prized in Chinese alchemy and is an important ingredient for making philosopher's stone, a mythical substance that is said to turn ordinary metals into gold, and medieval potions. Traditional Chinese medicine uses cinnabar powder to treat a variety of ailments, such as skin infections and intestinal ailments. Many cinnabar remedies are still used in TCM today.
Figure 19 Cinnabar carved objects, left: goblet carved with lychee and vine; The picture on the right shows a box carved with butterflies, gourds and vines
Cinnabar pigments are used extensively in Chinese lacquerware, and the use of this material dates back to 7000 BC and is still in production today. Lacquer is a resin, mainly derived from sumac trees, a plant in the family Sumacea, which, when exposed to oxygen and dried, turns into a heat-resistant, waterproof natural plastic. Lacquer ware is based on a rotating wood, coated with 30 to 200 layers of lacquer, which can be carefully carved into geometric patterns or carved into patterns representing land, water and sky. These items are usually painted red and called cinnabar paint.
Cinnabar is a man-made cinnabar that can be synthesized by wet or dry processes. The dry method may have been invented by China before it was introduced to the West through Arab traders, and the first records of this process originated in the 8th century. In the Middle Ages, mercury was mixed with molten sulfur and heated until the compound sublimated and condensed, and the product was a red crystal of mercury sulfide. It is then treated with an alkaline solution to remove sulfur. The wet process was invented in the 17th century, mixing mercury sulfide with a heated ammonium sulfide or potassium sulfide solution, which has a greater cost advantage and has become the most popular cinnabar production method in the West. Cinnabar was little known in the 8th century and became mainstream in the 14th century. Unlike malachite and azurite, cinnabar is highly absorbent and its color is preserved in all particle sizes.
Figure 20. Brushing Hair by Edgar Degas (1896), a tribute to the almost monochromatic red color, showcasing vermilion, red ochre and red lead pigments
Cinnabar is an important color in clay and gold decorative manuscripts, mainly used to paint red fonts and images. From the 14th century, it became a dominant color, appearing in the works of Vermeer (fig. 14), Titian (fig. 15) and Degas (fig. 20), and in the early 19th century, cadmium red began to be introduced and gradually replaced cinnabar. Cadmium-containing pigments are becoming the standard for bright, lightfast, weather-resistant yellows, reds and oranges.
7. Conclusion
Historically, many gemstones that can be used as pigments have had a dual mission, and both missions have retained their great value over time. While the beauty of gemstones is appreciated, it is often unclear to art audiences that from prehistoric to postmodern times, the colors in those popular paintings came from decorative materials, pigments and gemstones because of their ability to explain human understanding of the natural world, further intertwined with anthropological information, and with the advancement of chemistry, the synthesis of pigments and gemstones inevitably followed. The availability of various gem materials drove the development of pigments, which in turn created art history. Since art is only our reflection of the environment and our hearts, the dialogue of art also has an indelible contribution to the shaping of human beings themselves.
Original statement: This article only applies for originality for the translated and compiled content, and the copyright belongs to the original author.
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