Plaster fossils painted with gouache

About a week ago, we studied what a fossil is and how it is formed. There are many types of fossils and how they form is dependent on their makeup and material. Yet each one shares this common trait, they are fragile and take thousands if not millions of years to form. This is one way you can simulate what the earth does with rocks and movement over time in your own kitchen or right at you table. The things you will need are

-clay (in our case we used polymer clay, but I’m pretty sure anything thats tight and will hold a form will work. This is not the job for salt dough.)

-water

-plaster of paris

- fossils, shells, interesting dinosaur toys, etc.

Now the first step is to roll your clay into a sphere and smash it down to make a pancake. Then, press your fossil or shell into the clay. You’ll want to create a small border to catch all of the plaster for your Palentology goings on. This took a few times with the polymer clay and the plaster would leak from underneath! This didn’t seem to effect the clay very much, as it could be reshaped after the plaster dried a bit.

Next, after your molds have been made and a proper seal around the mold is sculpted, you pour the plaster into the molds. You’ll want to wait about 10 mins for the plaster to ‘set’ as if you don’t you will have a mess on your hands! Then leave the plaster in a sunny space to dry for about an hour. We watched a documentary on the origins of life on Amazon Prime while we waited.

After we waited a bit, we took them out of the molds. This reveal is so incredibly interactive and my 8 year old was so overjoyed at his creations, especially when they came out so well! We had so much fun with this science/art project.

Then we painted the plaster with gouache. The gouache paint is absorbed by the plaster of Paris as its application is water based but it looks so cool when it dries and really aids the earth tones in staying vibrant for a long time. After the paint was dried we sprayed them with a matte finish to stop our natural oils from lifting up the paint when we handled them later. There’s loads of great info on fossils but this we did on a Friday and we will carry this study with us into next week where we will handle the writing portion of these crafts and projects.

Have an excellent day!