Raw umber

Umber is a natural brown clay pigment which contains iron and manganese oxides. The color becomes more intense when calcined (heated), and the resulting pigment is called burnt umber. The name derives from Umbria, a mountainous region of central Italy, but it is found in many parts of the world. Some of the finest umber comes from Cyprus. It has been used as a pigment since prehistoric times. Raw umber pigment From an email dated Wed, 31 Mar 2004 21:25:29 -0800: You can use the images of pigments as long as you give full credit to Iconofile and the web site. ... Raw umber pigment From an email dated Wed, 31 Mar 2004 21:25:29 -0800: You can use the images of pigments as long as you give full credit to Iconofile and the web site. ... Clay is a generic term for an aggregate of hydrous silicate particles less than 4 μm (micrometres) in diameter. ... In biology, pigment is any material resulting in color in plant or animal cells which is the result of selective absorption. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7, 4, d Appearance silvery metallic Atomic mass 54. ... An oxide is a chemical compound of oxygen with other chemical elements. ... Umbria is a mountainous region of central Italy, in the valley of the river Tiber. ...

Chemical formula: Fe₂O₃ + MnO₂ + nH₂O + Si + Al₂O₃

See also: sienna, ochre, clay earth pigment This page is not about Siena, Italy. ... Ochre or Ocher (pronounced OAK-ur, from the Greek ochros, yellow) is a color, usually described as golden-yellow or light yellow brown. ... Clay earth pigments are naturally occurring minerals that have been used since prehistoric times as pigments. ...

External links

Discussion of umber and its use by Vermeer and other painters