ABSTRACTThe paper describes experimental rock weathering in a climatic chamber of about 90 different Swedish rocks. The specimens were when possible sawed into cubes with a side of about 7.5 cm. The amount of material released from Precambrian crystalline rocks after 324 freeze-thaw cycles is extremely low. Often the debris is less than 0.001% of the original weight. In spite of the low weathering rate a clear distinction can be seen between different rock types. The soft sedimentary rocks included in the experiment have produced between 400 and 5000 times more material of grain sizes smaller than 0.25 mm than the mean for granites. The amount of material produced after 252 wetting-drying cycles is on an average 10 times lower than in the freeze-thaw experiments.