Radioactive coins, got any?

I bought one of those souvenir irradiated Mercury dimes. A co-worker bought a Geiger counter. He was thinking there were some clandestine nuclear weapons establishments here in the South Bay. He said he wasn't worried about the fallout from the Japanese nuke power plant melt down, but the timing is a bit suspicious to me. Anyway I asked him to bring it in to work. I brought my dime. He wouldn't touch my dime but allowed me to operate the Geiger counter. Nope, nothing, not a beep. The fellow seemed disappointed to not have detected anything the entire time he has been is possession of his new toy.