Co-op Science: Types of Rocks

A couple of months ago I hosted another science class for preschool-1st grade age students.  This time we were studying the 3 different types of rocks - Metamorphic, Igneous, and Sedimentary.

We started off by having a rock show and tell.  I asked the kids to bring some rocks to share and I borrowed some fancy rocks from a friend to show off as well.

Igneous

Igneous rocks are formed from cooling magma and so to demonstrate this, we lit some small tea candles and had the children pour the liquid wax onto wax paper and let it harden.  This of course should be done with adult supervision!

 Sedimentary

Sedimentary rocks are formed from various layers of loose sediment being compacted and cemented together over time.  We demonstrated this by having the kids create layers of colored sugar in baby jars and pushing down with a spoon to compact them.  I was planning to purchase a sand art kit, but couldn't justify the cost.  The food dye colored sugar worked just as well.

Metamorphic

Metamorphic rocks are formed when pressure and heat are applied to any other form of rock.  We demonstrated this by giving the kids different colors of playdough and having them form layers to create a sedimentary rock.  They then pressed them between their hands as hard as they could - which of course applied both pressure, and body heat.  The melded result was their metamorphic rock.

Snack!

We ate a related snack as well!  I made a Sedimentary cheese sandwich and then applied heat (stove) and pressure (spatula) to create Metamorphic grilled cheese.  Then I gave the kids a small amount of vanilla ice cream with some magic shell poured over it.  The resulting shell after it hardened was their Igneous dessert.

This was so much fun and I could see the lightbulbs going off in their heads.  Good times!  Thanks for reading!