Mineral found in granite radiometric dating
There were other estimates but the calculations were hotly disputed because they all were obviously flawed by uncertainties in both the initial assumptions and the data.
Unbeknownst to the scientists engaged in this controversy, however, geology was about to be profoundly affected by the same discoveries that revolutionized physics at the turn of the 20th century.
These are also the methods most commonly criticized by creation “scientists.” For additional information on these methods or on methods not covered here, the reader is referred to the books by Faul (47), Dalrymple and Lanphere (35), Doe (38), York and Farquhar (136), Faure and Powell (50), Faure (49), and Jager and Hunziker (70), as well as the article by Dalrymple (32).
The K-Ar method is probably the most widely used radiometric dating technique available to geologists.
Second, the rock or mineral must not lose or gain either potassium or argon from the time of its formation to the time of analysis.
On the contrary, radiometric ages are verified whenever possible and practical, and are evaluated by considering other relevant data.For example, a method based on a parent isotope with a very long half-life, such as C method can only be used to determine the ages of certain types of young organic material and is useless on old granites.