CHANGES ROUGH STONES INTO SHINY GEMS + + Grinding the rocks against one another mimics the process of weathering and erosion + + Done mechanically, speeds up the natural process LEARN ABOUT + + Rocks (incl. rock types) + + Mechanical weathering and erosion + + Geology + + Nature and time 18 PIECE EXPERIMENT SET AGES 8+ ROCK TUMBLER KIT MINI EXPERIMENT KIT 31 30