Do you have a geology planned for your homeschool classroom. Or maybe you have a Dinosaur Theme Preschool Birthday Party to plan for? Either one would be a wonderful opportunity to try our DIY Fossils Project with your chidlren. Making your own fossils is great fun, and really not as “troublesome,” or “messy” as you might think! This craft really drives home the point in how fossils are formed and leaves children with a lasting impression!!

Make Your Own Fossils!


  • Plaster of Paris
  • Tinfoil
  • Small objects to fossilize!

Step 1: Making a Fossil Cast

Using your tinfoil, you’ll want to crumple and create a small circular container (as shown in the upper right-hand corner). You’ll need a tinfoil container for each fossil you want to create.

Next, you’ll shape your clay to fit inside the tinfoil container, as shown in the center of the photo. Your tinfoil container should be raised up higher than the clay.

Next, you’ll want to make impressions into your clay. You can do this using a variety of plastic children’s toys. Try insects, dinosaurs etc….and really push into the clay so that each tiny detail is transfered over.

Using toys that have texture or design to them will make for an extra detailed fossil. Just be sure all the little parts are carefully pressed into the clay.

Step 2: Making Plaster Fossils

In a separate container, you’ll want to mix your plaster of paris according to your specific product directions. Obviously, this is a job for Mom, Dad, or the teacher. Always carefully supervise your students when using these types of materials.

Once the plaster is mixed, you can use a small spoon to carefully fill in over the top of your clay impressions. Adding small amounts of plaster with each scoop ensures the plaster reaches inside the tiny areas in your impression.

You can use the back of the spoon to smooth out the top and fill in any areas that might need more coverage.

Once your casts are filled with plaster it’s time to wait for them to harden. This can take near an hour, so set them aside somewhere safe and come back to them in about 60 minutes.

Step 3: Reveal Your Fossils

After you are sure they are hardened, carefully peel back the tinfoil to reveal the clay and plaster. The plaster will be stuck to the clay, so you’ll want to carefully peel that back as well. Slow and steady so as not to break off any small areas.

Wow! Take a peek inside as your plaster cast! This fossil turnout out amasingly detailed, look at all the lines of texture on this spider!

And here is a peek at how our butterfly turned out! How pretty is that? If you look closely you can see all the lines in the body and wings. Plaster of Paris is fantastic for picking up all the intricate details.

And check out our millipede and all those tiny little legs!

Making your own fossils is a simple, yet exciting activity for students. If you are using this activity for educational purposes these would work well for any geology, biology, or archeology unit. If you are using this for a preschool discovery bin or a dinosaur themed birthday party, these would be fun to bury in a small sensory tub filled with sand for students to unearth and discover!


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