In September 1945 after detonation of the atomic bombs at Hiroshima and Nagasaki, a special investigation committee was organized by the National Research Council of Japan. The purpose of the committee was to study scientific, engineering and medical aspects of the atomic bomb catastrophe. In the geological and geographical field, in situ observation and sampling were performed from October to December in 1945. Many stones, bricks, roof tiles and ceramic products near the hypocenter were collected, which provided information on the effects of heat on various substances. Since then these samples have been preserved without disturbance at Hiroshima University, and have played an important role in the evaluation of atomic-bomb radiation studies through the measurement of residual radioactivities of 152Eu and 60Co, and fallout of 137Cs. These samples were consigned to the Hiroshima University Museum in 2014 for peace education and to serve peace education.