Definition - What does Earth Pigments mean?
Earth pigments are naturally occurring minerals, principally iron oxides, that have been used in paints for thousands of years for their natural color. They produce soft, earthy hues that can create vibrant colors and can protect material from corrosion.
Earth pigments are used in wood finishing to color oils, waxes, paints and varnishes, and they are also used to color plaster, whitewash, coating and glazes.
Corrosionpedia explains Earth Pigments
Earth pigments are pigments used in paints and obtained from the earth, including barytes, ochre, chalk and graphite. These natural pigments are found in rocks and soils around the world, where different combinations of minerals create vibrant colors that are unique to the regional landscapes. Some earth pigments are roasted in order to intensify their color.
Earth pigments have a good resistance to UV and are nontoxic. These pigments can provide aesthetic value, retention of gloss and color, as well as help with film structure and impermeability. They can improve the corrosion protection properties of a coating.
The primary types are of earth pigments include:
- Ochre - Comes from naturally tinted clay-containing mineral oxides, used for painting and preservation
- Sienna - A form of limonite clay, color is derived from ferric oxides
- Umber - A clay pigment that contains iron and manganese oxides, darker in color than ochres and sienna
Earth pigments are known for their fast drying time in oil painting, relative inexpensiveness and light fastness. Prehistoric cave paintings done in sienna still survive today.