One thing I bought was a starter rock collection containing five rocks of each of the three main types: igneous, sedimentary, and metamorphic. We also went on several nature walks and collected rocks - something my kids are doing all the time anyway! Since we are kind of limited in the types of rocks we have in our area, the purchased collection turned out to be a great investment. The kids have really enjoyed looking at and handling all of these rocks and doing different activities and experiments with them.
A few or our rock activities and experiments:
-Washing the rocks we found on our nature walks
-Sorting by color, size, shape, texture
-Ordering from smallest to largest
-Testing for hardness by scratching with our fingernail, penny, nail, and steel file
-Dropping in water to test for buoyancy
-Dropping in vinegar to test for calcite content. (If a rock contains the mineral calcite, bubbles will form in the vinegar.)
-Using a magnet to see if any of our rocks contain iron or other magnetic minerals
-We've also drawn rocks in our nature journals.
We're leaving in the morning for an overnight field trip to Red River Gorge in Kentucky. There is a natural bridge there that was formed from sandstone plus lots of hiking trails and opportunities to hopefully see some different kinds of rocks. This will be the grand finale to our study of rocks and minerals!