How to Make Fossils With Plaster of Paris

Fossils are the imprints left behind from animal and plant life that roamed the earth hundreds of thousands of years ago. While many museums have dinosaur fossils on display, the most common fossils are of small shells and other sea life. You can make your own fossils with plaster of Paris. This plaster is available at hobby or craft stores, and sets up quickly. This is a good project for science classes, homeschool families, or those who are interested in dinosaurs and biology.

Things You'll Need

• Plaster of Paris Shells Vegetable oil Plastic spoon Paper cups Paper towel

Instructions

1. Choose one to three small shells, and coat them in a thin layer of vegetable oil. Place them in the bottom of a large paper cup.

2. Mix 1 part plaster of Paris to 2 to 2 1/2 parts cold water in a disposable cup. Combine well so that the mixture is smooth and not lumpy.

3. Spoon the plaster of Paris over the shells, covering them with 1 to 1 1/2 inches of plaster. Set aside to dry for 1 to 2 hours.

4. Tear the cup away from the dry plaster. Flip the plaster disk over and peel the shells up.

5. Wipe excess vegetable oil off the plaster with a paper towel. Paint or display the fossil as desired.

Tips & Warnings

• Mix a pinch or two of salt with the plaster mix to quicken drying time. Mix 1 tbsp. sand to 1 cup dry plaster before adding water to make a rockier looking fossil. Small bones, such as from a chicken, can be used instead of shells.

• Cover the work area well and wear old clothes.

References

• Scholastic