Raw umber: Difference between revisions
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[[File:Raw.umber_det.jpg|thumb|Raw umber]] | [[File:Raw.umber_det.jpg|thumb|Raw umber]] | ||
== Description == | == Description == | ||
[[File:564 raw umber.jpg|thumb|Raw umber]] | |||
A pale yellowish brown natural earth pigment that contains [[manganese%20dioxide|manganese dioxide]] and [[ferric%20hydroxide|iron hydroxide]]. See [[umber|umber]]. | A pale yellowish brown natural earth pigment that contains [[manganese%20dioxide|manganese dioxide]] and [[ferric%20hydroxide|iron hydroxide]]. See [[umber|umber]]. | ||
== Synonyms and Related Terms == | == Synonyms and Related Terms == | ||
Pigment Brown 7; CI 77492; umbra; terre d'ombre naturelle (Fr.); Umbra natur (Deut.); | Pigment Brown 7; CI 77492; umbra; terre d'ombre naturelle (Fr.); Umbra natur (Deut.); ombra omi (Gr.); terra d'ombra naturale (It.); ruwe omber (Ned.); grisaille; Sicilian brown | ||
Note: All iron oxide pigments made after 2001 are designated Pigment Brown 6 (not 7) | |||
== Risks == | == Risks == | ||
| Line 15: | Line 15: | ||
== Physical and Chemical Properties == | == Physical and Chemical Properties == | ||
Slightly soluble in acids giving a yellow solution. Turns reddish brown when heated. | * Slightly soluble in acids giving a yellow solution. | ||
* Turns reddish brown when heated. | |||
* Density = 3.2 g/ml | |||
* Refractive Index = 1.87-2.17 | |||
== Additional Images == | == Additional Images == | ||
<gallery> | <gallery> | ||
File:21_Raw umber_500X.jpg|Raw umber | File:21_Raw umber_500X.jpg|Raw umber at 500s<br> transmitted light | ||
File:21_Raw umber_500X_pol.jpg|Raw umber | File:21_Raw umber_500X_pol.jpg|Raw umber at 500x<br>Polarized light | ||
</gallery> | </gallery> | ||
| Line 35: | Line 30: | ||
* R. J. Gettens, G.L. Stout, ''Painting Materials, A Short Encyclopaedia'', Dover Publications, New York, 1966 Comment: density = 3.20 and ref. index = 1.87-2.17 | * R. J. Gettens, G.L. Stout, ''Painting Materials, A Short Encyclopaedia'', Dover Publications, New York, 1966 Comment: density = 3.20 and ref. index = 1.87-2.17 | ||
* Michael McCann, ''Artist Beware'', Watson-Guptill Publications, New York City, 1979 | * Michael McCann, ''Artist Beware'', Watson-Guptill Publications, New York City, 1979 | ||
* R.D. Harley, ''Artists' Pigments c. 1600-1835'', Butterworth Scientific, London, 1982 | * R.D. Harley, ''Artists' Pigments c. 1600-1835'', Butterworth Scientific, London, 1982 | ||
* ''Dictionary of Building Preservation'', Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996 | * ''Dictionary of Building Preservation'', Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996 | ||
* Pigments Through the Ages - http://webexhibits.org/pigments/indiv/overview/umbra.html | * Pigments Through the Ages - http://webexhibits.org/pigments/indiv/overview/umbra.html | ||
* Website: http://www.coloria.net/varita.htm | * Website: http://www.coloria.net/varita.htm | ||
* Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000 | * Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000 | ||
* CHSOS: [https://chsopensource.org/products/pigments-checker/pigments-checker-4/pigments-checker-standard-pigments-list/raw-umber-k-40610/ Spectra (Reflectance, XRF, Raman, FTIR) for Raw umber] | |||
[[Category:Materials database]] | [[Category:Materials database]] | ||
Latest revision as of 15:20, 2 March 2026
Description
A pale yellowish brown natural earth pigment that contains manganese dioxide and iron hydroxide. See umber.
Synonyms and Related Terms
Pigment Brown 7; CI 77492; umbra; terre d'ombre naturelle (Fr.); Umbra natur (Deut.); ombra omi (Gr.); terra d'ombra naturale (It.); ruwe omber (Ned.); grisaille; Sicilian brown
Note: All iron oxide pigments made after 2001 are designated Pigment Brown 6 (not 7)
Risks
Toxic.
Physical and Chemical Properties
- Slightly soluble in acids giving a yellow solution.
- Turns reddish brown when heated.
- Density = 3.2 g/ml
- Refractive Index = 1.87-2.17
Additional Images
Raw umber at 500s
transmitted light
Raw umber at 500x
Polarized light
Resources and Citations
- R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966 Comment: density = 3.20 and ref. index = 1.87-2.17
- Michael McCann, Artist Beware, Watson-Guptill Publications, New York City, 1979
- R.D. Harley, Artists' Pigments c. 1600-1835, Butterworth Scientific, London, 1982
- Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
- Pigments Through the Ages - http://webexhibits.org/pigments/indiv/overview/umbra.html
- Website: http://www.coloria.net/varita.htm
- Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000
- CHSOS: Spectra (Reflectance, XRF, Raman, FTIR) for Raw umber