When I took a radiation protection class as part of my Master's degree, the prof brought in an orange dish glazed with uranium as an ingredient in the colour. Again, what a great colour! (The pedagogic purpose was to try out different types of radiation detectors to determine what type of radiation was being emitted by the plate - since it was alpha radiation it doesn't even go through your skin, so it wasn't exactly dangerous for us in class It's only dangerous when it's inside your lungs or gut!) In the same lesson we checked out the radiation from a radium dial watch, and two different types of smoke detectors - one commercial, one for home use. It was a really neat class.