Chrome yellow

![American school bus, painted in traditional Chrome yellow[4]](/Images/godic/202501/04/Laidlaw_school_bus5336.jpg")
Chrome Yellow is lead(II) chromate (PbCrO4). It occurs naturally as the mineral crocoite but the mineral itself was never used as a pigment in paintings. After the French chemist Louis Vauquelin discovered the new element chromium in 1797 lead chromate has been synthetized in the laboratory and its use as a pigment started in the second decade of the nineteenth century.