An earth pigment of a brownish-yellow color when raw, and an orange-red or reddish-brown when burnt. The color comes from the oxides of iron and manganese.

An earth pigment of a yellowish-brown, or reddish-brown color used in paints, stains and fillers. The color is derived from the presence of oxides of iron and manganese.

Sienna is a form of limonite clay most famous in the production of oil paint pigments. Its yellow-brown colour comes from ferric oxides contained within. As a natural pigment, it (along with its chemical cousins ochre and umber) was one of the first pigments to be used by humans, and is found in many cave paintings.