Miss McKendrick's Fourth Grade Class Make "Fossils"

In Miss McKendrick's class the last few weeks we have been learning about different ways creatures and tracks can be fossilized. One way is for a dinosaur to fall into a body of water and over time the bone cells are filled with mineral water. The minerals harden, the bone wastes away, and what is left is the fossil (hardened minerals/rock) in the exact same shape as the dinosaur from long ago. Our class demonstrated this by having the dinosaur bones (sponge) fall into the water (sodium silicate). Then after some time it filled in all of the cells of the dinosaur (sponge holes) and hardened into a fossil! We used our imaginations of course! We had a great time and learned a lot.