Sedimentary Rocks: Make Your Own Sandstone
by Deborah Hanuscin
Concept: Sandstone formation.
Sandstone is formed through the processes of weathering, transport, deposit, burial, and lithification, as described in Sedimentary Snack Bars. It is made up of small (between .0625 mm and 2 mm) particles of sediment that are bound together by a cement.
Objective:
Students will be able to describe how sedimentary rocks are formed.
Materials:
- coarse sand
- two paper cups per student or group
- water
- Epsom salts
- magnifying lenses
- samples of sandstone (available from Indiana Geological Survey as part of the Indiana Rock Set)
Procedure:
- Pour about one inch of coarse sand into a paper cup.
- Pour about one inch of water in a second paper cup and add Epsom salts slowly while stirring until no more will dissolve.
- Pour the Epsom salts solution over the sand in the cup. Stir well to mix.
- Place the mixture where it will be undisturbed for several days until it is dry.
- When it is dry, carefully tear the paper cup away from the sand.
Questions:
- Describe what you observe. Use a magnifying lens to examine your "rock."
- What is holding your rock together? Where are the Epsom salts?
- Compare your rock to the sandstone samples. Which is harder? Why?