Part iron, part oxygen, part clay and soil, ochre is an earth pigment. It is both color and material. Crush it up, add liquid, and the pigment becomes a fluid color material—paint. For some 500,000 years, ochres and peoples have coevolved. But ochre, like the earth itself, is much, much more than simply how people have chosen to use it, be that for art or technology or any space in between.