orpiment

The Latin auripigmentum (aurum, "gold" + pigmentum, "pigment") referred both to its deep-yellow color and to the historical belief that it was thought to contain gold. The Latin term was used by Pliny in the first century CE.{{Cn|date=April 2023}}

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.{{Cite book |last=Fitzhugh |first=Elizabeth West |title=Artists' Pigments: A Handbook of Their History and Characteristics, Volume 3 |publisher=Archetype Publications |year=1997 |isbn=978-1-904982-76-0 |location=Washington |pages=48–70 |chapter=Orpiment and Realgar}}

The Chinese term for orpiment is Ci-Huang (in Pinyin), meaning "female yellow".{{Cite journal |last=Schafer |first=Edward H. |date=1955 |title=Orpiment and Realgar in Chinese Technology and Tradition |url=https://www.jstor.org/stable/595009 |journal=Journal of the American Oriental Society |volume=75 |issue=2 |pages=73–89 |doi=10.2307/595009 |jstor=595009 |issn=0003-0279|url-access=subscription }}

The Persian for orpiment is zarnikh, deriving from the word "zar", the Persian for gold.{{Cn|date=April 2023}}

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 {{convert|300|°C|°F|-1}} to {{convert|325|°C|°F|-1}}. Optically, it is biaxial (−) with refractive indices of a = 2.4, b = 2.81, g = 3.02.

File:Orpiment - streak color.jpg of orpiment|186x186px]]

File:Realgar and orpiment-2.jpg

Orpiment is a type of lemon-yellow to golden- or brownish-yellow crystal commonly found in foliated columnar or fibrous aggregates, may alternatively be botryoidal or reniform, granular or powdery, and, rarely, as prismatic crystals.{{Cite web |title=Realgar and Orpiment – Arsenic Sulfide Minerals |url=https://geology.com/minerals/realgar-orpiment.shtml |access-date=2023-04-15 |website=geology.com}} Used as a pigment, orpiment's color is often described as a lemon- or canary-yellow, and occasionally as a golden- or brownish-yellow.

In the Munsell color system, "orpiment" is designated "brilliant yellow", Munsell notation 4.4Y 8.7 /8.9.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.

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.

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.

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.{{Cite journal |last1=Keune |first1=Katrien |last2=Mass |first2=Jennifer |last3=Mehta |first3=Apurva |last4=Church |first4=Jonathan |last5=Meirer |first5=Florian |date=2016-04-21 |title=Analytical imaging studies of the migration of degraded orpiment, realgar, and emerald green pigments in historic paintings and related conservation issues |journal=Heritage Science |volume=4 |issue=1 |pages=10 |doi=10.1186/s40494-016-0078-1 |s2cid=40318538 |issn=2050-7445 |doi-access=free |hdl=11245.1/080e76f8-43f1-4464-afa3-8b9646e2484a |hdl-access=free }}{{Creative Commons text attribution notice|cc=by4|from this source=yes}}

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.{{cn|date=April 2023}}

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.

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.

File:RAFAEL - Madonna Sixtina (Gemäldegalerie Alter Meister, Dresden, 1513-14. Óleo sobre lienzo, 265 x 196 cm).jpgIn Egypt, lumps of orpiment pigment have been found in a fourteenth-century BC tomb.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. 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|date=April 2023}}.{{Cite journal |last=Garner |first=Henry |date=1963-08-01 |title=Technical Studies of Oriental Lacquer |url=https://doi.org/10.1179/sic.1963.013 |journal=Studies in Conservation |volume=8 |issue=3 |pages=84–98 |doi=10.1179/sic.1963.013 |issn=0039-3630|url-access=subscription }} In a traditional Thai painting technique, still in use today, yellow ink for writing and drawing on black paper manuscripts is made using orpiment.{{Cite journal |last=Pearman |first=Sara Jane |date=April 1977 |title=Thai Painting . Jean Boisselier , Janet Seligman |url=https://www.journals.uchicago.edu/doi/10.1086/arlisnanews.5.3.27945831 |journal=ARLIS/NA Newsletter |language=en |volume=5 |issue=3 |pages=102–103 |doi=10.1086/arlisnanews.5.3.27945831 |issn=0090-3515|url-access=subscription }}

Medieval European artists imported orpiment from Asia Minor.{{CN|date=April 2023}} 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 Orthodox icons 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.

File:Wilton diptych.jpg

File:Jacopo Tintoretto - Portrait of Vincenzo Morosini - WGA22697.jpg

In the Medieval Norwegian church of Tingelstad, orpiment was used in painting the altar frontal.{{cn|date=April 2023}}

Orpiment was commonly combined with indigo dye to make a dark, rich green.{{cn|date=April 2023}} In the Wilton Diptych (c 1395-9), this green pigment was used in egg tempera on the left panel for the green cloak of Edmund the Martyr.{{cn|date=April 2023}}

File:Giovanni Bellini and Titian - The Feast of the Gods - Google Art Project.jpg

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.{{Cite web |title=Raphael, Sistine Madonna |url=https://colourlex.com/project/raphael-sistine-madonna/ |access-date=2024-05-04 |website=ColourLex |language=en-US}}

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.{{Rp|page=49}}

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.St. Clair, Kassia (2016). The Secret Lives of Colour. London: John Murray. pp. 82–83. {{ISBN|978-1-4736-3081-9}}. {{OCLC|936144129}}.

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{{Cite book|url=https://books.google.com/books?id=2PmrPnUY_3YC&q=orpiment+%22fly+poison%22&pg=PA246|title=Popular philosophy: or, The book of nature laid open upon Christian principles, by the ed. of The Cheap magazine|last=Miller|first=George|date=1826|language=en}} and to tip arrows with poison.{{Cite book|url=https://books.google.com/books?id=3jZBAQAAMAAJ&q=poison+arrows|title=Mesny's Chinese Miscellany|last=Mesny|first=William|date=1899|publisher=China Gazette Office.|language=en}} 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.{{Cite book |last=St. Clair |first=Kassia |title=The Secret Lives of Colour |publisher=John Murray |year=2016 |isbn=978-1-4736-3081-9 |location=London |pages=82–83 |oclc=936144129}} 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.{{cite web |url=http://news.xinhuanet.com/newscenter/2006-07/29/content_4890298.htm |title=雌黄在古代充当"涂改液" |website=news.xinhuanet.com |access-date=9 August 2022 |archive-url=https://web.archive.org/web/20160806100548/http://news.xinhuanet.com/newscenter/2006-07/29/content_4890298.htm |archive-date=6 August 2016 |url-status=dead}} Orpiment is mentioned in the 17th century by Robert Hooke in Micrographia for the manufacture of small shot.{{cite web|last=Hooke|first=Robert|title=Micrographia|url=http://www.gutenberg.org/files/15491/15491-h/15491-h.htm|publisher=Project Gutenberg|access-date=24 October 2012}} Scientists like Richard Adolf Zsigmondy and Hermann Ambronn puzzled jointly over the amorphous form of {{chem|As|2|S|3}}, "orpiment glass", as early as 1904.{{cite book | chapter=Richard Adolf Zsigmondy: Properties of Colloids | title=Nobel Lectures, Chemistry 1922–1941 | chapter-url=http://nobelprize.org/nobel_prizes/chemistry/laureates/1925/zsigmondy-lecture.html | location=Amsterdam | publisher=Elsevier Publishing Company | year=1966 }}

Orpiment is used in the production of infrared-transmitting glass, oil cloth, linoleum, semiconductors, photoconductors, pigments, and fireworks. Mixed with two parts of slaked lime (calcium hydroxide), orpiment is still commonly used in rural India as a depilatory. It is used in the tanning industry to remove hair from hides.

Orpiment has been used as bookends. In 2023, the UK Office for Product Safety and Standards recalled 40 pieces sold by TK Maxx between June and October 2022, due to the mineral's toxicity.{{cite web |last1=Mcneil |first1=Daniel |title=Government issue recall of household accessory from TK Maxx & Homesense – what to do |url=https://www.yorkshireeveningpost.co.uk/read-this/government-issue-recall-of-household-accessory-from-tk-maxx-homesense-what-to-do-4042935 |website=Yorkshire Evening Post |access-date=18 April 2023 |date=27 February 2023}}{{cite web |title=Product Recall: Yellow Orpiment Mineral Bookends sold by TK Maxx (2302-0126) |url=https://www.gov.uk/product-safety-alerts-reports-recalls/product-recall-yellow-orpiment-mineral-bookends-sold-by-tk-maxx-2302-0126 |website=GOV.UK |access-date=18 April 2023 |language=en |date=24 February 2023}}

File:Orpiment-unit-cell-3D-balls.png|{{center|Orpiment's unit cell}}

File:Orpiment-layer-3D-balls.png|{{center|Orpiment's crystal structure consists of sheets}}

File:Orpiment-layers-stacking-3D-balls.png|{{center|The sheets are stacked into layers}}

File:Orpiment.ვკ.jpg|Orpiment from Racha, northern Georgia region

File:Orpiment-Realgar-Quartz-154641.jpg|Orpiment and realgar on a vuggy, quartz matrix, Nishinomaki Mine, Gunma Prefecture, Japan

File:MFN MIN 1977 0028 Auripigment.jpg|Orpiment from La Libertad, Quiruvilca, Peru

File:Orpiment-d06-185b.jpg|El'brusskiy arsenic mine, Kabardino-Balkarian Republic, Northern Caucasus Region, Russia

• List of inorganic pigments

{{Reflist}}

• [http://webexhibits.org/pigments/indiv/overview/orpiment.html Webexhibits "Pigments Through the Ages: Orpiment"]
• [http://dafyomi.org/index.php?masechta=chulin&daf=88b Babylonian Talmud Tractate Chullin] see Rashi 'haZarnich' {{in lang|he}}
• [http://colourlex.com/project/orpiment/ Orpiment], Colourlex

{{Commons category| Orpiment}}

Category:Arsenic minerals

Category:Sulfide minerals

Category:Inorganic pigments

Category:Alchemical substances

Category:Monoclinic minerals

Category:Minerals in space group 14

Category:Blendes