Why is u 238 used for dating rocks
The radiometric dater then uses the half-life of all four isotopes to find an age range the rock should be in.
Another benefit is that zircon has been found in most igneous rocks.
The benefits of using zircon is that the trapping temperature is 900 C.
This temperature makes the zircon hard to pull out substances out of it.
Most radiometric daters prefer using zircon for these reasons, but it is not the only compound used for uranium-lead dating.
Some other compounds used that have zirconium are zirconolite, and badeleyite.
With all radiometric dating processes, the accuracy of uranium-lead dating is called into question.