Uranium-lead radiometric dating is most often performed on the mineral
Uranium-lead dating is usually performed on the mineral zircon (ZrSiO 4), though it can be used on other minerals. Zircon incorporates uranium and thorium atoms into its crystalline structure, but strongly rejects lead. Therefore, we can assume that the entire lead content of the zircon is radiogenic. Where this is not the case, a correction.