Native Ferric Oxide as a Pigment
In nature, ferric oxide forms extensive deposits, which, by reason of the light red colour characteristic of certain varieties of ferric oxide, are largely employed in painting. These colours may be classed among the oldest known to mankind, ferric oxide pigments having been used frequently in the most ancient paintings.
The most important varieties of ferric oxide for our purpose are: iron glance, with its modifications, micaceous iron ore and frothy hematite; red hematite, and raddle.