ocher (ōˈkər) [key], mixture of varying proportions of iron oxide and clay, used as a pigment. It occurs naturally as yellow ocher (yellow or yellow-brown in color), the iron oxide being limonite, or as red ocher, the iron oxide being hematite. Ocher grades into sienna, a yellow-brown pigment containing a higher percentage of iron ore than ocher as well as some manganese dioxide; sienna grades into umber, which is darker brown and contains a higher percentage of manganese dioxide. Burnt sienna is brown or bright red; burnt umber is a darker brown than umber. Ocher is produced in the United States, in France (French ocher being of a very high grade), and in some other parts of Europe. Italy is a leading producer of sienna and umber, and Cyprus of umber.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on ocher from Fact Monster:

  • umber - umber: umber: see ocher.
  • sienna - sienna: sienna: see ocher.
  • limonite - limonite limonite or brown hematite, yellowish to dark brown mineral, a hydrated oxide of iron, ...
  • hematite - hematite hematite , mineral, an oxide of iron, Fe2O3, containing about 70% metal, occurring in ...
  • Persepolis - Persepolis Persepolis [Gr.,=city of Persia], ancient city of Persia, ceremonial capital of the ...

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