Iron Oxide Red - many types

Iron oxide pigment
Natural iron oxide pigments include a combination of one or more ferrous or ferric oxides and such impurities as clay, manganese, or organics. Synthetic iron oxides can be produced in various ways; these include calcining, precipitation, and reduction thermal decomposition of iron compounds. Typical colors are black, brown, red orange, and yellow. Iron oxide pigments are lightfast, nonbleeding, nontoxic, and weather resistant so they are widely used to color concrete blocks, outdoor paints, and other construction materials. Less than one-half of the iron oxide pigments used in the United States is mined and processed domestically. The main source of imported material is China.