Lead lead dating
If the two people already have the same type of herpes, no problem for dating. What you are referring to is actually called Uranium-Lead dating, a form of radioactive decay dating based on how long it takes various Uranium isotopes to decay to their ultimate stable daughter Lead isotopes. No form of radioactive dating produces exact results.
There have been alot of cases with young girls dating and stuff on the internet and stuff that lead to there disappearance or worse.Other minerals sometimes used for uranium-lead dating include monazite, titanite and two other zirconium minerals, baddeleyite and zirconolite.However, zircon is so overwhelming a favorite that geologists often just refer to "zircon dating." But even the best geologic methods are imperfect.With 238U the Pb/U ratio grows much more slowly with age, but the idea is the same.If you took rocks of all ages and plotted their two Pb/U ratios from their two isotope pairs against each other on a graph, the points would form a beautiful line called a concordia (see the example in the right column).