I recently went on a rock collecting trip, but apart from the usual — quartz, K feldspar crystals, garnet, etc — I found some slightly radioactive rocks: ~5 CPS above background on contact with the RC-102. ~13 CPS above background on contact with the RC-102. ~20 CPS above background on contact with the RC-102. ~40 CPS above background on contact with the RC-102. All of these were found using my prospecting scintillator, but I took measurements with a Radiacode 102 — a very common hobbyi...
