Lamellar pigments are based on iron oxide of the general formula Mn.sub.X Al.sub.Y Fe.sub.2 -(X+Y)O.sub.3, where X is from 0.01 to 0.06 and Y is from 0 to 0.2. The pigments are prepared by hydrothermal treatment of an aqueous suspension which contains an iron hydroxide or iron oxide hydroxide,and an alkali metal hydroxide and/or alkali metal carbonate, in the presence of a manganese compound which is soluble in the reaction medium and in the presence or absence of an aluminum compound.The pigments are used for pigmenting coatings, printing inks, finishes, plastics, ceramic surfaces, glasses and cosmetic products.