5-6 years

Posted on Nov 27, 2014 | Resources

Magic Treasure Rock

Suggested age: Kindergarten to 2nd grade

Submitted by Tisha Aragaki, State Librarian, Hawaii State Library


Sylvester and the Magic Pebble by William Steig

If Rocks Could Sing: a Discovered Alphabet by Leslie McGuirk

This storytime and activity is a fun way to explore rocks in both fantastical and realistic form. The books are great introductions to varying shapes sizes and compositions of rocks and minerals. The activity itself is more for tactile play but can be more appropriately adapted by putting various types of minerals in the rocks as treasures. Polished rocks and minerals can easily be found at educational toy stores. To keep the content(s) of the rock a surprise, parents can prepare the “magic treasure rocks” for their children, or they can do the craft together.


Activity: Magic Treasure Rocks

The activity is from the parenting blog, www.growingajeweledrose.com, and was shared with us through Maryknoll Librarian, Tina Arakawa.


  • Baking soda
  • water
  • Food coloring or washable watercolors to make the rocks.
  • Vinegar
  • A large bowl to dissolve the rocks in later


  1. Add the baking soda into a large bowl, as much as desired.
  2. If you’d like color or sparkle, add a few drops of food coloring and a dash or two of glitter.
  3. Slowly add water and mix. Gradually add more water until the mixture is damp and moldable, but not wet and mushy. (It is easy to add too much water. If you do accidentally add too much water, just add a little more baking soda.)
  4. Once mixed, mold the baking soda dough into balls, hiding treasures inside. We have used polished crystals (most exciting and even better for discussing rocks and minerals), plastic jewels, old coins and other small toys.
  5. Then put the rocks on a cookie sheet or similar to dry. Drying will take roughly 24 hours.
  6. Once dry you can either give them right to your child or hide them by burying outside or perhaps in a treasure chest. (At the library we have used colorful shredded paper in a chest to make discovery fun and relatively clean.)


  1. After the treasure rocks have been “found,” fill your large bowl with vinegar and let your child put the rocks in one at a time.


  1. The treasure rocks will dissolve into a fun, bubbly fizz and reveal the treasure in the middle! They can also be cracked open, as the rocks fall apart easily, or sprayed with vinegar for a slightly more suspenseful dissolve.



See https://www.growingajeweledrose.com/2013/01/magic-treasure-rocks.html