Red ochre is composed mailnly of iron oxide, hematite which word comes from Greek, hema meaning blood. Used from prehistory and throughout history, these permanent pigments can be safely mixed with other pigments. Ochres vary widely in transparency; some are quite opaque, while others are valued for their use as glazes.
Red ochre consists of silica and clay owing its color to iron oxide. It is found throughout the world, in many shades, in hues from yellow to brown, and faint blue. The best brown ochre comes from Cyprus.