Thorite - Kemp Uranium Mine, Cardiff Township, Ontario, Canada, Geiger counter gamma
Here is a thorite specimen about one inch
from a Geiger Counter. The specimen is about 1 1/2 " and seems to be solid
thorite. Thorite is thorium uranium silicate, (Th, U)SiO4. Its two radioactive
elements give off plenty of alpha, beta and gamma radiation on their way
down to lead. This Geiger counter isn't designed to read
alpha particles and it was not positioned for reading beta so all radiation
described on this page is gamma.
The camera caught the meter at almost 0.3
mR/hr (milli-Roentgen per hour ) of gamma radiation but at this low reading
the needle fluctuates wildly. The procedure for reading levels below 0.1
mR/hr is to count the clicks. About 330 clicks ( or counts) per minute
corresponds to 0.1 mR/hr.
