This specification details the properties and requirements for the pigment commercially known as black synthetic iron oxide, which is manufactured ferrous-ferric oxide obtained by chemical reaction. It shall be a soft dry finely powdered pigment, free of admixtures of other substances. Specimens shall be sampled, chemically tested, and conform accordingly to specified values of the following requirements: total iron oxides (as ferrous and ferric oxide); ferrous iron in iron oxide; water-soluble matter; moisture and other volatile matter; coarse particles (total residue retained on a No. 325 sieve); hydrogen ion concentration (pH value); and mass color, tint character, and tinting strength.