[en] Research at all 373 schools in the Austrian province of Salzburg showed that 88 schools have a larger geological collection. In 13 of these schools (11%) a total of 44 radioactive rocks were found whose existence were unknown to the current teaching staff. Due to the storage locations and accordingly to a low local dose rate of most of the samples, an acute endangerment of pupils and teachers could be excluded in all 13 cases, but considering the potential hazard of radiation, the rock samples were removed from the geological collections at the request of the schools.