Editing Sienna

{{short description|Earth pigment}}
{{about|the clay used for pigments|the Italian city|Siena|other uses}}
{{Use American English|date=June 2013}}
{{infobox color
| title     = Sienna
| hex       = 882D17
| spelling  = color
| source    = <ref>{{cite web|url=http://tx4.us/nbs/nbs-s.htm |title=ISCC-NBS|url-status=usurped | archive-url=https://web.archive.org/web/20121122220208/http://tx4.us/nbs/nbs-s.htm |archive-date=22 November 2012 }}</ref>
| isccname  = Strong reddish brown}}

'''Sienna''' ({{etymology|it|{{wikt-lang|it|terra di Siena}}|earth of Siena}}) is an [[earth pigment]] containing [[iron oxide]] and [[manganese oxide]]. In its natural state, it is yellowish brown, and it is called '''raw sienna'''. When heated, it becomes a reddish brown, and it is called '''burnt sienna'''.<ref name="Shorter OED">''Shorter Oxford English Dictionary'', 5th Edition (2002)</ref> It takes its name from the city-state of [[Republic of Siena|Siena]], where it was produced during the [[Renaissance]].<ref>''Webster's New World Dictionary of the American Language,'' College Edition, (1964)</ref> Along with [[ochre]] and [[umber]], it was one of the first pigments to be used by humans, and is found in many [[cave painting]]s. Since the Renaissance, it has been one of the brown pigments most widely used by artists.

The first recorded use of ''sienna'' as a color name in [[English language|English]] was in 1760.<ref>Maerz and Paul ''A Dictionary of Color'' 1930 New York: McGraw-Hill p. 204; Color Sample of Sienna: p. 37 Plate 7 Color Sample E12</ref>

The [[Wikipedia:WikiProject Color/Normalized Color Coordinates|normalized color coordinates]] for sienna are identical to [[Indian red#Kobe|kobe]], first recorded as a color name in English in 1924.<ref>Maerz and Paul ''A Dictionary of Color'' New York:1930 McGraw-Hill p. 197; Color sample of Kobe: p. 35 Plate 6 color sample K12</ref>

==Earth colors==
Like the other earth colors, such as [[yellow ochre]] and [[umber]], sienna is a clay which is partially composed of [[iron oxide]]s. In the case of sienna, the most prevalent iron oxides are [[limonite]] (which in its natural state has a yellowish color), and [[goethite]]. In addition to iron oxides, natural or raw sienna is also composed of [[manganese oxide]], which makes it darker than ochre. [[Aluminium oxides|Aluminum oxides]] have also been found in the soil at very low levels.<ref name="Helwig-2007">{{Cite book |last=Helwig |first=Kate |title=Artists' Pigments |publisher=Archetype Publications |year=2007 |isbn=978-1-904982-234 |volume=4 |pages= |chapter=Iron Oxides}}</ref> When heated, the limonite and goethite is dehydrated and turns partially to [[haematite|hematite]], which gives it a reddish-brown color.<ref>{{cite book
|url=https://books.google.com/books?id=6Z3bAXEM_xwC&q=sienna&pg=PA161
|title=Blue and yellow don't make green
|last=Wilcox
|first=Michael
|publisher= School of Color
|pages=172, 161
|year=2002
|access-date=October 19, 2009
|isbn= 0-9679628-7-0 }}</ref>
Sienna is lighter in shade than raw umber, which is also clay with iron oxide, but which has a significantly higher content of manganese (5 to 20 percent) making it greenish brown or dark brown in color. When heated, raw umber becomes burnt umber, a very dark brown.<ref name="Roelofs-2012"/>

<gallery>
File:Monteriggioni0001.jpg|The clay soil of Tuscany (here near [[Monteriggioni]])  is rich in limonite, or hydrated iron oxide, the main component of sienna pigment.
File:LimoniteUSGOV.jpg|[[Limonite]], a clay containing iron oxide, which gives sienna pigment its color.
File:Hematite.jpg|[[Haematite]]. When roasted, limonite is converted partially to [[haematite]] and its colors turns more reddish.
File:Pigment sienna burnt iconofile.jpg|After heating, the pigment becomes the color burnt sienna.
</gallery>

==History==
The pigment sienna was known and used in its natural form by the ancient Romans. It was mined near [[Arcidosso]] (formerly under Sienese control, now in the [[province of Grosseto]]) on [[Monte Amiata]] in southern [[Tuscany]]. It was called ''terra rossa'' (red earth), ''terra gialla'' (yellow earth), or terra di Siena''.''{{Citation needed|date=April 2023}}

In the [[Middle Ages]] the sienna pigments were used by artists such as [[Duccio|Duccio di Buoninsegna]] and other painters who lived and worked in and around the [[Republic of Siena]].<ref name="Manasse-2006">{{Cite journal |last1=Manasse |first1=Andrea |last2=Mellini |first2=Marcello |date=2006-12-20 |title=Iron (hydr)oxide nanocrystals in raw and burnt sienna pigments |url=https://www.schweizerbart.de/papers/ejm/detail/18/57371/Iron_hydr_oxide_nanocrystals_in_raw_and_burnt_sien?af=crossref |journal=European Journal of Mineralogy |volume=18 |issue=6 |language=en |pages=845–853 |doi=10.1127/0935-1221/2006/0018-0845|bibcode=2006EJMin..18..845M }}</ref> Duccio was painting with earth pigments in the late 13th century until his death in the early 14th century.{{Citation needed|date=April 2023}}

During the [[Renaissance]], [[Giorgio Vasari]] made note of the pigment under the name terra rossa. Along with umber and yellow ochre, sienna became one of the standard browns used by artists from the 16th to 19th centuries, including [[Caravaggio]] (1571–1610) and [[Rembrandt]] (1606–1669), who used all three earth colors in his palette.<ref name="Burnet-1880">John Burnet (1880), A Treatise on Painting in Four Parts, (Google Books)</ref><ref name="Bomfeld-1988">David Bomfeld, Christopher Brown, Ashok Roy, (1988) I ''Rembrandt – Art in the Making''. Yale University Press, ({{ISBN|978-0-300-06145-1}}).</ref> Cross sections of Rembrandt's works, analyzed by X-Ray and infrared lenses, reveal that he used variations of sienna to prime his paintings. This was especially true for some of his later works.<ref>{{Cite journal |last=Plesters |first=Joyce |date=1956 |title=Cross-Sections and Chemical Analysis of Paint Samples |url=https://www.jstor.org/stable/1505000 |journal=Studies in Conservation |volume=2 |issue=3 |pages=122–125 |doi=10.2307/1505000 |jstor=1505000 |archive-date=2022-11-17 |access-date=2025-01-09 |archive-url=https://web.archive.org/web/20221117165015/https://www.jstor.org/stable/1505000 |url-status=live }}</ref>

Although these artists are known to have used sienna and its variations in their works, scholars have pointed out that the pigment was not commonly referenced by name in European sources until the mid-eighteenth century.<ref name="Helwig-2007" />{{Rp|page=52}}

By the 1940s, the traditional Italian sources of the pigment were nearly exhausted. Much of today's sienna production is carried out in the [[Insular Italy|Italian islands]] of [[Sardinia]] and [[Sicily]], while other major deposits are found in the [[Appalachian Mountains]], where it is often found alongside the region's iron deposits. It is also still produced in the French Ardennes in the small town of Bonne Fontaine near Ecordal.<ref name="Roelofs-2012">{{cite book
|last= Roelofs
|first= Isabelle
|title= La couleur expliquée aux artistes
|year= 2012
|publisher= Groupe Eyrolles
|isbn= 978-2-212-134865}} p. 30</ref> It is important to note that the chemical composition of the umbers produced in France are distinctly different from the original siennas.{{Citation needed|date=April 2023}}

In the 20th century, pigments began to be produced using synthetic iron oxide rather than natural deposits. The labels on paint tubes indicate whether they contain natural or synthetic ingredients. PY-43 indicates natural raw sienna, while PR-102 indicates natural burnt sienna.

<gallery>
File:Giorgio Vasari - The battle of Marciano in Val di Chiana - Google Art Project.jpg|[[Giorgio Vasari]] (1511–1574) used earth colors, including ochre and sienna, in his frescos such this in the Hall of the Five Hundred at the [[Palazzo Vecchio]] in Florence.<ref>Web exhibits, Pigments through the Ages.</ref> In his writings Vasari referred to sienna as ''terra rossa''.<ref>Giorgio Vasari, Lives of the Most Eminent Painters, Sculptors and Architects. (Google Books).</ref>
File:Rembrandt Self-portrait (Kenwood).jpg|[[Rembrandt]] van Rijn used all the earth pigments (sienna, ochre, and umber) to create his rich and complex browns.<ref name="Burnet-1880"/><ref name="Bomfeld-1988"/>
</gallery>

== Historical preparation ==
Historically, the pigment was prepared by taking lumps of earth and placing them into a fire either using a crucible or shovel, in order to induce the necessary chemical reaction. In some seventeenth-century accounts, the lumps of earth are supposed to be pulverized, or at least broken down into smaller pieces, first. However, the instructions from the time period are inconsistent. Furthermore, the amount of time that the pigment needs to be heated is based on what the artist preparing the pigment desires. Generally, a longer exposure to heat leads to a deeper red hue.<ref>{{Cite journal |last=Helwig |first=Kate |date=1997 |title=A Note on Burnt Yellow Earth Pigments: Documentary Sources and Scientific Analysis |url=https://www.jstor.org/stable/1506714 |journal=Studies in Conservation |volume=42 |issue=3 |pages=181–188 |doi=10.2307/1506714 |jstor=1506714 |issn=0039-3630 |archive-date=2023-04-16 |access-date=2025-01-09 |archive-url=https://web.archive.org/web/20230416200139/https://www.jstor.org/stable/1506714 |url-status=live }}</ref>

==Shades and variations==

Sienna varies slightly in shade and hue based on the chemical composition of the soil and the temperature and length of time in which it is prepared. A higher composition of iron oxide in the soil leads to a deeper red pigment.<ref>{{Cite web |title=Color Clues: What can soil tell you? |url=https://www.asec.purdue.edu/soilhealth/downloads/ColorClues,SWS2.pdf |access-date=February 2, 2024 |website=Agricultural Sciences Education and Communication, Purdue University |archive-date=February 3, 2024 |archive-url=https://web.archive.org/web/20240203001801/https://www.asec.purdue.edu/soilhealth/downloads/ColorClues,SWS2.pdf |url-status=live }}</ref>

There is no single agreed standard for the color of sienna, and the name is used today for a wide variety of hues and shades. They vary by country and color list, and there are many proprietary variations offered by paint companies. The color box at the top of the article shows one variation from the ISCC-NBS color list.<ref>{{Cite web |title=ISCC-NBS Colour System |url=https://www.munsellcolourscienceforpainters.com/ISCCNBS/ISCCNBSSystem.html |access-date=2024-02-03 |website=www.munsellcolourscienceforpainters.com}}</ref>

===Raw sienna===
{{infobox color
|title=Terra di Siena naturale, or raw sienna (Italian)
|hex=965434
|spelling=colour
|source=[[Ferrario 1919: Cartella colori]],<ref name="ferrario">{{Cite web|url=http://www.ferrariospa.it/DocsImgs/Docs/cartColori_ferrario1919.pdf|title=cartColori_ferrario1919|website=www.ferrariospa.it}}</ref> colour 69
|isccname=Strong brown}}
Raw sienna is a yellowish-brown natural earth pigment,<ref name="Shorter OED"/> composed primarily of iron oxide hydroxide. The box shows the color of the pigment in its natural, or raw state. It contains a large quantity of iron oxide and a small quantity (about five percent) of manganese oxide.

This kind of pigment is known as yellow ochre, yellow earth, limonite, or terra gialla. The pigment name for natural raw sienna from the [[Colour Index International|Color Index International]], shown on the labels of oil paints,  is PY-43.

This box at right shows a variation of raw sienna from the Italian Ferrario 1919 color list.
{{Clear}}

===Burnt sienna===
{{infobox color
|title=Terra di Siena bruciata, or burnt sienna (Italian)
|hex=623034
|spelling=colour
|source=[[Ferrario 1919: Cartella colori]],<ref name="ferrario"/> colour 77
|isccname=Deep reddish brown}}

'''Burnt sienna''' contains a large proportion of anhydrous iron oxide. It is made by heating raw sienna, which dehydrates the iron oxide, changing it partially to hematite, giving it rich reddish-brown color.<ref name="Shorter OED"/>

The pigment is also known as red earth, red ochre, and terra rossa. On the [[Colour Index International|Color Index International]], the pigment is known as PR-102.

This version is from the Italian Ferrario 1919 color list.

The first recorded use of ''burnt sienna'' as a color name in English was in 1853.<ref name="Maerz-1939">Maerz and Paul ''A Dictionary of Color'' 1930 New York: McGraw-Hill p. 204; Color Sample of Sienna: p. 33 Plate 5 Color Sample F12</ref>

{{Clear}}

====Burnt sienna pigment (Maerz and Paul)====
{{infobox color
| title     = Burnt sienna (Maerz and Paul)
| hex       = E97451
| spelling  = colour
| source    = Maerz and Paul<ref name="Maerz-1939"/>
| isccname  = Strong reddish orange}}
This variation of burnt sienna is from the Maerz and Paul "A Dictionary of Color" from 1930. It is considerably lighter than most other versions of burnt sienna. It was a mix of [[burnt orange]] and raw sienna.
{{Clear}}

===Dark sienna (ISCC-NBS)===
{{infobox color
| title     = Dark sienna
| hex       = 3C1414
| spelling  = colour
| source    = {{usurped|1=[https://web.archive.org/web/20121122220828/http://tx4.us/mr/mr3c.htm ISCC-NBS]}}<ref>{{cite web |url=http://tx4.us/mr/mr3c.htm |archive-url=https://web.archive.org/web/20121122220828/http://tx4.us/mr/mr3c.htm |url-status=usurped |archive-date=22 November 2012 |title=THE MOTHER OF ALL HTML COLOR CHARTS RGB order page #3C (Part of the ISCC-NBS color list)|last=Foster |first=John C. |author2=Texas Precancel Club  |date=1 April 2006 |access-date=August 16, 2012}}</ref>
| isccname  = Dark reddish brown}}
This infobox shows the color '''dark sienna''' from the ISCC-NBS color list.
{{Clear}}

===Sienna (X11 color)===
{{infobox color
| title = Sienna (X11 web colour)
| hex = A0522D
| spelling = colour
| source =[[List of HTML color names|X11]]
| isccname = Strong brown}}
The [[web colour|web color]] sienna is defined by the list of [[X11 colours|X11 colors]] used in web browsers and web design.
{{Clear}}

==See also==
* [[Lists of colors]]
* [[List of inorganic pigments]]

==References==

{{reflist}}

{{Shades of brown|sienna}}

[[Category:Iron oxide pigments]]
[[Category:Shades of brown]]