Orpiment takes its name from the Latin auripigmentum (aurum, "gold" + pigmentum, "pigment"), due to its deep-yellow color. Orpiment once was widely used in artworks, medicine, and other applications. Because of its toxicity and instability, its usage has declined.
Etymology
The Latin auripigmentum (aurum, "gold" + pigmentum, "pigment") referred both to its deep-yellow color and to the historical belief that it contained gold. The Latin term was used by Pliny in the first century CE.[citation needed]
The Greek for orpiment was arsenikon, deriving from the Greek word arsenikos, meaning "male", from the belief that metals were of different sexes. This Greek term was used by Theophrastus in the fourth century BC.[5]
The Chinese term for orpiment is Ci-Huang (in Pinyin), meaning "female yellow".[6]
The Persian for orpiment is zarnikh, deriving from the word "zar", the Persian for gold.[citation needed]
Physical and optical properties
Orpiment is a common monoclinic arsenic sulfide mineral. It has a Mohs hardness of 1.5 to 2 and a specific gravity of 3.49. It melts at 300°C (570°F) to 325°C (620°F). Optically, it is biaxial (−) with refractive indices of a = 2.4, b = 2.81, g = 3.02.
Visual characteristics
Bright golden-yellow streak color of orpimentOrpiment and Realgar on the same rock
In the Munsell color system, "orpiment" is designated "brilliant yellow", Munsell notation 4.4Y 8.7 /8.9.[8]
Orpiment and realgar
Orpiment and realgar are closely related minerals and are often categorized in the same group. They are both arsenic sulfides and belong to the monoclinic crystal system. They are found in the same deposits and can form in the same geologic environments. As a result, orpiment and realgar share similar physical properties and histories of use by humans.[7]
In Chinese, the names for orpiment and realgar are Ci-Huang and Xiong-Huang, respectively meaning "female yellow" and "male yellow". Their names symbolize their close natural conjunction, both physically in terms of their occurrence and properties and culturally in Chinese traditions.
Orpiment and realgar can be distinguished by their different visual characteristics. While orpiment typically has a vibrant golden-yellow color, realgar, in contrast, normally has an orange or reddish hue.[6]
Permanence and conservation
Yellow orpiment (As2S3) degrades into arsenic oxides. Because of their solubility in water, arsenic oxides readily migrate to the surrounding environment. In painted works using orpiment, migrating, degraded arsenic oxides are often detectable throughout the multi-layered paint system. This widespread arsenic migration has consequences for the conservation of orpiment as a pigment in works of art.[9]
Orpiment is also sensitive to light exposure, decaying into a friable white arsenic trioxide over time. Similarly, on ancient, orpiment-coated manuscript paper in Nepal, orpiment used to deter insects has often turned white over time.[citation needed]
Because of orpiment's solubility and instability as a pigment, preventing the degradation of orpiment may need to be prioritized in art conservation. Proper conservation methods should minimize exposure to strong light. Such methods should emphasize humidity control and avoid the use of water-based cleaning agents.[9]
Use by artists
Orpiment has historically been used in artworks in many locales in the Eastern Hemisphere. It was one of the few clear, bright-yellow pigments available to artists until the 19th century.
Historical and regional use of orpiment
Raphael (1483–1520), Sistine Madonna (1513–14)
In Egypt, lumps of orpiment pigment have been found in a fourteenth-century BC tomb.[10] In China, orpiment is known to have been used to color Chinese lacquer, despite no written sources mentioning this. Orpiment has also been identified on Central Asian wall paintings from the sixth to the thirteenth centuries[specify].[11] In a traditional Thai painting technique, still in use today, yellow ink for writing and drawing on black paper manuscripts is made using orpiment.[12]
Medieval European artists imported orpiment from Asia Minor.[citation needed] Orpiment has been identified on Norwegian wooden altar frontals, polychrome sculptures, and folk art objects, including a crucifix. It was also used in twelfth- to sixteenth-century Eastern Orthodoxicons from Bulgaria, Russia, and the former Yugoslavia. In Venice, records show that orpiment was purchased for a Romanian prince in 1600. European use of orpiment was uncommon until the nineteenth century, during which it saw use as a pigment in Impressionist paintings.[5]
Anonymous, The Wilton Diptych (c 1395-9), The National Gallery, London.Jacopo Tintoretto (c 1518–1594), Portrait of Vincenzo Morosini, The National Gallery (Presented by the Art Fund), London.
Giovanni Bellini (c. 1430–1516) and Titian (−1576), The Feast of the Gods (1514–1529), National Gallery of Art, Washington, DC. Wikimedia Commons.
Renaissance artists such as Raphael also used orpiment as a yellow pigment. In Raphael's Sistine Madonna from 1513–14, orpiment is used to achieve yellow on the clothing of the figures and in the background.[13]
Tintoretto's Portrait of Vincenzo Morosini from about 1575–80 uses the pigment in its details. Orpiment is used to replicate the gold embroidery on Morosini's embroidered stole and to highlight the fur of the spotted ferret on his chest.[5]:49
Limitations
Orpiment was one of the few clear, bright-yellow pigments available to artists until the 19th century. Its extreme toxicity and incompatibility with other, common, pigments, including lead and copper-based substances such as verdigris and azurite, meant that its use as a pigment ended when cadmium yellows, chromium yellows and organic aniline dye-based colors were introduced during the 19th century.[14]
Other historical uses
Orpiment was traded in the Roman Empire and was used as a medicine in China, even though it is very toxic. It has been used as fly poison[15] and to tip arrows with poison.[16] Because of its striking color, it was of interest to alchemists, both in China and Europe, searching for a way to make gold. It also has been found in the wall decorations of Tutankhamun's tomb and ancient Egyptian scrolls, and on the walls of the Taj Mahal.[17] For centuries, orpiment was ground down and used as a pigment in painting and for sealing wax, and was even used in ancient China as a correction fluid.[18] Orpiment is mentioned in the 17th century by Robert Hooke in Micrographia for the manufacture of small shot.[19] Scientists like Richard Adolf Zsigmondy and Hermann Ambronn puzzled jointly over the amorphous form of As 2S 3, "orpiment glass", as early as 1904.[20]
↑Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Orpiment"(PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 14 March 2022.
123Fitzhugh, Elizabeth West (1997). "Orpiment and Realgar". Artists' Pigments: A Handbook of Their History and Characteristics, Volume 3. Washington: Archetype Publications. pp.48–70. ISBN978-1-904982-76-0.
↑Kelly, K.L.; Judd, D.B. (1955). The ISCC-NBS Method of Designating Colors and a Dictionary of Color Names (Circular 553 ed.). Washington: U.S. Department of Commerce, National Bureau of Standards.
↑Saleh, S.A. (1987). "Pigments, Plasters, and Salts Analyses," Wall Paintings of the Tomb of Nefertari: Scientific Studies for Their Conservation. Cairo, Egypt and Century City, Calif. pp. 94–105.
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