Waterford Crystal – A beautiful addition to any home! It shines, looks lovely, and it is radioactive!
I recently tested a piece of Waterford crystal to see why it was radioactive. For a long time I have wondered by my Geiger counter went crazy when near it. The truth was quickly revealed by Gamma Spectroscopy! The little Angel statue contained potassium 40, (element K). All potassium contains 93+ % Potassium 39, stable potassium, and a little bit of the isotope Potassium 41, perhaps 6+ %. But, all potassium also contains a tiny fraction of the radioactive isotope of potassium, Potassium 40 (K40). Potassium 40 undergoes three forms of decay, beta -, rarely beta+, and electron capture. The last step emits a gamma ray with an energy of 1461 keV. It is this gamma ray that I detected.