Rocks-Minerals

We finish our unit on geology this week, reviewing how rocks are formed. We discuss how rocks are made from minerals, which are the "ingredients" of rocks and are made from chemicals called elements. We talk about the difference between rare minerals such as diamonds, and common minerals such as quartz, and about how people use minerals. Most minerals grow by forming crystals, like snowflakes!

We talk about how minerals are important to our bodies and how we get them. Sodium and chlorine form the most important rock that humans need to ingest to maintain life - salt. We look at the process of creating rock salt with a sodium solution on a mirror. As the water is evaporated away, the sodium chloride crystals form on the mirror. We are creating an experiment in class to demonstrate crystal formation. We are filling a jar with a highly salted water solution and suspending a string in it so the crystals can attach as they dry. We hope to see real crystal growth over the next few weeks.

Rocks are used in everyday life.  

We will attempt to make homemade pretzels and sprinkle rock salt liberally on them for good taste!!
We will make treasure boxes to take home and go on a rock hunt on the playground to start our own collection.

Books: Let's Go Rock Collecting by Roma Gans; The Story of Salt by Mark Kurlansky