Classroom Activity: Coffee Ground Fossils

BY Sarah Conn
Stuck inside with nothing to do this holiday season? Looking for a fun, hands-on activity to supplement your digital learning?

Filament Games has you covered!

If you enjoy learning about fossils (or you’ve played our popular unity and diversity learning game Fossil Forensics), I encourage you to try making your own Coffee Ground Fossils!

This project simulates the creation of imprint or impression fossils. Unlike the fossils found in Fossil Forensics, imprint fossils do not contain carbon material- rather, their distinct shapes are created by the absence of a fossil. Sometimes this is due to the tissue rotting away – other times this means that the fossil is part of a paired set (one impression fossil and one compression fossil consisting of mineralized remains). Most imprint fossils are created in fine grained and moist sediment. Once the first sediment layer dries, more sediment covers the imprint, leaving the fossil preserved.

Some experts have found imprint fossils of dinosaur tracks and plants...pretty neat if you ask me!

Ready to make your own?

What you will need:
  • 1 cup used coffee grounds
  • ½ cup cold coffee
  • 1 cup flour
  • ½ cup salt
  • Wax paper
  • Mixing bowl
  • Objects for impression (shells work well, but you can use anything with an interesting shape or texture)
  • Newspapers or some kind of table cover
  • One cup or cookie cutter
  • Optional: toothpicks, string

  1. Set up your workspace by covering it with newspaper.
  2. Stir together coffee grounds, coffee, flour, and salt until a dough forms.
  3. Knead dough and then turn out and flatten onto wax paper with hands.
  4. Using your cup or cookie cutter, cut out circles or shapes out of the flattened dough.
  5. Press small objects firmly into the dough to leave an imprint. When you remove the object, your fossil has been formed!
  6. You can use a toothpick to poke a hole in the dough so you can thread your fossils.
  7. Let your fossils harden, undisturbed, overnight. Depending on how thick the dough is, it may take longer.

Want to learn more about fossils? Check out Fossil Forensics, one of the many quality educational games available in the Filament Learning library!