Making Fossils in the Classroom

I'm sitting in my living room.
In sweatpants.
Wearing a fuzzy sweater.
Drinking a steamy cup of hot tea.
Listening to the rain.
Catching up on a blog reading.
I am one happy little teacher :)

We have been studying fossils in science - and this fun project was the perfect culmination to end our study...

Here's all you need for each student:
100 mL of Plaster of Paris (I bought mine at Michaels)

50 mL of water:

Styrofoam cup
(Don't use paper - it won't work as well)

a paper plate:
a ball of modeling clay:
and a small toy that you want to imprint:
I gave my kids an assortment to choose from: dinosaurs, reptiles, and farm animals :)

1.Cut the Styrofoam cup about 1/3 of the way from the top
2. Place the top 1/3 of the cup (open on both ends) on a paper plate and press the modeling clay into the bottom
3. Choose an animal and press down into the clay, making an imprint. Remove animal.
4. In the bottom 2/3 of the Styrofoam cup, mix 100 mL of Plaster of Paris with 50 mL of water.
5. Pour the mixture over the clay imprint.
6. Let harden over night.
7. After it is hard, peel away the Styrofoam
8. You should be able to clearly see the two layers (the clay and the plaster of Paris)
9. Carefully pull away the clay layer. 

I had the students roll the clay back into a ball (to use for next year)
They got to keep the fossil imprint:

10. VOILA! Enjoy your fossil :)

The students LOVED their fossils! They couldn't wait to take them home and show them off :) 


  1. OMG. The tree turned out great! What a clever lesson!


  2. Wow Jessica! Your fossils turned our awesome! What a great way to end a unit! I love it! Thanks for sharing the directions and pictures-I'm a visual learner! :O)
    So glad you shared and linked up friend!!!
    Head Over Heels For Teaching

  3. Awesome! Wonder if I could incorporate this into social studies somehow...


  4. This is so great!! I can see why the students would just love this. Your pictures and detailed directions are the best. Thanks for sharing!

  5. How fun is this! Thank you so much for sharing. I would definitely love to try this with my students. I bet they would really dig it!
    Rockin' and Lovin' Learnin'


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