Ingredients
- Baking soda: 1 cup
- Vinegar: For the fizz reaction
- Food coloring (optional): A few drops
- Molds or containers: Enough to hold the mixture and treasure
- Small treasures: Small toys or coins that fit comfortably in the mold
- Mixing bowl: 1
- Tray or workspace: 1
Instructions
- Put the baking soda into a mixing bowl. If you want colored rocks, add a few drops of food coloring and stir them through.
- Add a small amount of water and mix it in. Continue adding water a little at a time until the baking soda feels damp but not wet.
- Put a small toy, coin, or other chosen treasure into each mold or container.
- Spoon the damp mixture into the mold around the treasure. Press down firmly to compact it.
- Leave the filled molds undisturbed for a few hours or until the mixture is completely dry.
- Gently release each rock from its mold. Handle dry rocks carefully and place them on a tray.
- Set the rocks in the tray. Pour vinegar over them and watch the reaction.
- Once the fizzing has slowed, remove the treasures from the tray.
Notes
An adult should supervise the vinegar step, especially with younger children. These rocks are made for immediate use, not for permanent storage.
