red lead; minium; lead(II,IV) oxide
A bright red or orange-red lead oxide used historically as a pigment and in rust-proof paints. Technical term in chemistry.
Red lead was once widely used as a pigment in anti-corrosion paints.
In chemistry class, I learned that the chemical formula of red lead is Pb₃O₄.
From Chinese 鉛丹 (qiāndān), literally 'lead cinnabar/red', referring to the red color of the compound.