ules that end in “ite” actually exist. Why can't we make kryptonite?. The answer is no, we can't. The reason is twofold. Dr. Gerald Aardsma explains, " Radiocarbon is not used to date the age of rocks or to determine the age of the earth. Other radiometric dating methods such as potassium-argon or rubidium- strontium are used for such purposes by those who believe that the earth is billions.