Ochre (rarely spelled ocher and often referred to as yellow ochre) is one of a variety of forms of iron oxide which are described as earth-based pigments. ... Red oxides or red ochres are hematite-rich forms of yellow ochres, commonly formed from aerobic natural weathering of iron-bearing minerals.

How is Ochre made?

Colored earth is mined, ground and washed, leaving a mixture of minerals - essentially rust-stained clay. Ochre can be used raw (yellowish), or roasted for a deeper (brown-red) color from loss of water of hydration. Produces a quick-drying oil paint.

What kind of rock is Ochre?

Ochre is most commonly defined by archaeologists as any iron-rich rock that can be used as a pigment. Most people associate the term with hematite, or red ochre, chemically known as Fe2O3.