Are you using the same type counter? My 6" Fiestaware plate (pre-war plate (1936-1943), glaze with natural uranium) reads over 30 000 CPM when tested with an alpha sensitive GM counter. Uranium is an alpha emitter and these GQ 300 and 320e counters are not alpha capable - they can only register strong betas and gamma radiation.
Cactus has an anti radiation properties
Nice Experiment!
Your plate is fairly low my Geiger counter reads about 3,000 cpm and your is only 450 U think that's what you said
Are you using the same type counter? My 6" Fiestaware plate (pre-war plate (1936-1943), glaze with natural uranium) reads over 30 000 CPM when tested with an alpha sensitive GM counter. Uranium is an alpha emitter and these GQ 300 and 320e counters are not alpha capable - they can only register strong betas and gamma radiation.
Actually I have a GMC 300e plus Geiger counter but my one that read 3,000 was my cdv-700 an old cold war Geiger counter from 1960
I have the gmc500 plus lol