I have a little bit of dinosaur bone from a field course in Montana (taken legally, fyi) that is pretty radioactive. Uranium in groundwater will preferentially deposit in phosphates and organic material. Colin and I measured the bone tonight and used a matrix suggested by the geiger counter manufacturer to determine the content of the radiation.
The bare bone measured 181 uR/hr when placed just above the detector window.
It measured 170 uR/hr with a sheet of paper between the window and the bone (and a plastic bag).
With a 1/16inch thick sheet of aluminum, the count rate was 42 uR/hr (with plastic bag).
The rate was 15uR/hr from behind the detector and 12 uR/hr from the side. The background was ~14uR/hr.
This suggests 11uR/hr of alpha particles (helium nuclei);
128uR/hr of beta radiation (electrons); and
42uR/hr from gamma rays.
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