Amazingly, Coleman-type camping lanterns used to contain some radioactive thorium oxide. It's an incandescent material that greatly increases the light output of the lantern when it's heated in the flame. There are non-radioactive alternatives, mainly other rare earth oxides, but they are more expensive. We know this mantle contains radioactive thorium because the donor, who works for the Environmental Health & Safety department at the University of Illinois at Urbana-Champaign, tested it with a Geiger counter.
The sound for this sample is from the Geiger counter.
I've got one mantle in a lead cup in the table, and another one in the Hot Box.
Source: Hardware Store
Contributor: Trish Craig
Acquired: 28 May, 2002
Text Updated: 12 March, 2007