Hello. I found this forum thread when I was searching for rock dust and Azomite. We tested our Azomite with a calibrated Soeks geiger counter which detects gamma radiation. We found an average of 0.15 microSieverts per hour with a 15 minute test. Our back ground radiation in Daytona Beach is usually around 0.09 - 0.11 micro Sieverts per hour outside. The background radiation level goes up during cold front rain storms. At the end of 2011 our background readings were 0.06 micro Seiverts per hour.
I did note that the Azomite web page had radiation test results for only Alpha and Beta radiation, but not gamma.
.png)
