Yes, you can calculate the age of a geological sample with radioactive dating. All you need to do is calculate the actual composition of radioactive content in the sample. Then compare it with the usual content that is present. This will allow you to calculate the number of years it has been present depending on the amount of radioactive carbon left in the sample.
The half-life can be calculated easily and with that you can calculate the amount of years that the sample has aged. It is important to know the actual content of radioactive carbon, so that you can manage to find the years depending on the half-life.