A savvy shopper borrowed a Geiger counter from work to test her new granite before purchasing. She found that she was about to buy 360 square feet of uranium ore.



Bobbie Moreau selected five slabs of green and red Jupurana Vyara for her bathroom. A friend mentioned that some granite is radioactive, so Bobbie decided to find out for herself. She borrowed a Geiger counter from work and scanned the granite she had selected.



Bobbie was stunned by the readings on her Geiger counter. Background radiation outside the showroom was 2-7 counts/second. Then she went inside and measured her Jupurana Vyara. The granite set off the threshold alarm on her Geiger counter each time she got close.



Bobbie’s Geiger counter read 50-70 counts/second at two inches from the surface of her granite, about ten times the background radiation outside the shop. She immediately showed her readings to a sales representative, “which incited instant hostility and aggression”. The sales person told her that radioactive granite was a “wives tale” even as the Geiger counter sounded its alarm.



Bobbie feels she has “dodged a bullet” by testing her granite before buying. Many of the slabs she tested were no more radioactive than background, so she has many choices available. However, we suspect she will choose to do business with a vendor that is more ethical.



A general rule of thumb is to avoid granite that reads more than three times background. A client last year had granite that read about ten times background radiation. Lab analyses showed that her granite contained as much uranium as commercial uranium ore.



Geiger counters and Micro-R meters can sometimes be borrowed from hospitals or university physics departments. A number of companies rent meters, and they will ship to any location. In the Bay Area, industrial hygienists can test granite in a showroom or in the home.



Be cautious of granite vendors that offer to test their products themselves. Some granite yards use meters that only detect high-level radiation. Those vendors use inappropriate meters to convince buyers that no granite emits any radiation.



An ethical granite vendor will acknowledge that some granite is radioactive. Ethical vendors do not object to buyers testing their granite prior to purchase, and they do not object to buyers having professionals test for them.