This didactic museum belonging to the University of Wrocław - part of a snooze-worthy tag team with the Geology Museum in the same building - has rocks a'plenty, with one collection called 'Minerals of the World According to Classification and Chemical Structure' and another strictly devoted to domestic Polish minerals. In other words, it's about as interesting as a box of rocks. If you're really crazy for cleavage (the way minerals split in preferred directions to create smooth planes - what, you never studied geology?) we recommend visiting the somewhat larger branch of the Mineralogy Museum closer to the market square (ul. Kuźnicza 22; open 10:00-15:30, closed Sun), which features more exotic gems, meteorites, and ornamental stones, as well as a shop where you can purchase them. Rock on.