In reply to Jones Beene's message of Fri, 10 Apr 2015 12:48:35 -0700: Hi, [snip] >which is why even small pitchblende samples make the Geiger >counter go wild.
Try putting a sheet of paper between the Geiger counter and the pitchblende. I think you will find that it makes a huge difference. Most of the activity detected is due to alphas emitted from the surface. (Got your saw handy? ;) Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html