Wednesday, October 15, 2014
DIY: Fossil Rocks
This is a great activity to pair with a lesson about prehistoric life or any old rainy day. The recipe is simple and uses common kitchen ingredients, allows for a lot of customization, and it is easy for children to participate.
This project uses a very popular no-heat play dough recipe.
- 1 cup of warm water
- 1 cup of table salt
- 2 tablespoons of cooking oil
- 3 cups of flour
- 2 tablespoons of corn starch
- food coloring or tempera paints
Combine the salt, water, oil, and corn starch in a large mixing bowl. Stir in food coloring or tempera paint to reach desired shade (Note: rocks have very subtle coloring, but bright hues are more fun!). Slowly add flour while stirring then knead to a consistent texture. Wrap the dough to keep it from drying and allow the it to rest for at least 30 minutes to cool to room temperature before continuing.
Once you have your play dough, it's time to make an impression! Make a palm-sized lump of dough to use for your "rock" base. Children may want to play with the dough, but if it warms up or is worked too much the wheat proteins will activate and make a sticky mess!
Take your item to be "fossilized" and press it into the dough. We used some handy animal stamps that we had, but any small plastic toys can be used for this step. The dough lump should now be about the size and shape of a cookie. Place the "fossils" some place cool and dry. Slips of paper help to keep whose and where's straight
The last step of this process, just like real fossils, is waiting. You won't have to wait for millennia for your fossils to form, though. If you flip the dough imprints each day, they should be dry and hard within a few days. Heating will speed this process, but beware, they will crack if they dry too quickly.
Once your fossils are dried through they are ready for discovering!