This beautiful orange-red pigment approaches in composition a compound of two molecules of protoxide of lead with one molecule of binoxide, and may be approximately represented by the formula Pb3O4. The paler and more orange-tinted varieties contain an excess of protoxide of lead, often accompanied by a little carbonate.

This pigment is peculiarly liable to discoloration in the presence of sulphuretted hydrogen: it acts energetically upon some paints, on the cadmium yellows, for example. It is quite inadmissible as a water-colour, and cannot be considered as safe in oil.