|The coffee mixture made pretty convincing rocks. After a full day of basking in the sun, they dried nearly, well, as hard as rocks!|
First, Tessa rubbed sandpaper over a rock to simulate wind blowing grains of sand against large rocks.
|Tessa rubbed sandpaper over a mock rock.|
Next, she placed a rock in a jar of water and shook it to simulate waves crashing against a cliff.
|After shaking a rock in a jar of water, Tessa checked for changes.|
Finally, Tessa dropped and hit rocks together to see what would happen.
|Tessa learned that when large rocks collide, they break into smaller rocks. In time, those smaller rocks turn into sand or soil.|
|A close-up of one of Tessa's changed rocks.|
Tessa and I both greatly enjoyed this experiment. It well-suited her age and cemented in her mind the various ways rocks are changed by natural forces.