The Radiacode gamma spectrometer is a fun toy! My daughter discovered that this Mosasaur jaw we have is radioactive! It contains Bismuth-214, likely from uranium ore decay. The radiation is about 10x the background level, a bit more than the Am-241 smoke detectors in my house.

I bought this (from https://www.radiacode.com) after re-watching the excellent ‘Chernobyl’ mini-series. There’s a scene where Belarusian scientists are surprised by a radiation alert and test a sample of dust to find that it’s Uranium nuclear fuel fallout. Easy to do apparently!