Here’s How:

1. In a bowl, mix 1/2 cup of epsom salts (magnesium sulfate) with 1/2 cup of hot tap water (hot as it will get from the faucet).
2. Stir for about a minute to dissolve the epsom salts. There will still be some undissolved crystals at the bottom.
3. Pour the solution into the container of your choosing and add food coloring! We used oval soap molds which can be found at your local craft store.
4. Place your containers of solution in the refrigerator. After three hours* you should begin to see the crystals forming. Leave them in longer and track your progress!

*We left ours in the refrigerator for a couple of days, until all of the liquid evaporated. This was really cool because we were able to see the crystal structures more clearly and they got much bigger than we expected!

We would love to see your Epsom Salt Geodes! Send us pictures on our Facebook or to mkovalcik@gscm.org.

Project originally found at About.com.