PROJECT:
Identify rocks that kids have found in the field
GOAL:
To distinguish and identify the different types of rocks and to learn to use a rock and mineral guide
AGES:
Seven to 12
MATERIALS:
• Various rock specimens• A rock and mineral guide
• Spray bottle
• Paintbrush or toothbrush
• Paper plates or blank stickers
• One hand lens (10X magnification) for each child
• Paper and pencils
At the amateur level, identifying rocks is a fairly straightforward process, perfect for young rock hounds. You look for visual clues, answer a series of questions and, with the help of a rock and mineral guide, draw your conclusions. For kids who've started a rock collection, this is an enormously satisfying result.
With minerals, however, you need to answer a series of complex questions regarding crystal structure and specific gravity (yikes!). Keep to the philosophy that works best: do only what your kids can easily handle and enjoy.
STEP 1: WASHING THE ROCKS
Begin either at the kitchen sink or outside with a bucket of water, where the kids can clean all their samples. A nice, hard hunk of slate can be immersed in water and scrubbed clean, while a more fragile specimen will require gentler treatment. With softer specimens, a spray bottle and a paintbrush or toothbrush are the best tools for the job. While you might want to supervise this production, be sure to give the job to the children: The difference between a dirty specimen dug out of a hillside and the same piece after a good bath can be quite dramatic.
STEP 2: ROCK IDENTIFICATION
Spread your clean specimens out on the kitchen table, taking care to keep track of their numbers. Press a numbered sticker to each rock, or set each specimen on a paper plate marked with its own number, and remind the kids to keep all the rocks with their plates. Set out the rock and mineral books, and the children's hand lenses, and be sure there's adequate light. Give each child a pencil and a sheet of paper for keeping track of information. Each book has its own procedure for arriving at rock identifications, but of the ones we tried, we had good luck with the system outlined in the Eyewitness Handbook, ROCKS AND MINERALS, by Chris Pellant.
Rather than asking the kids to start with sample number one and continue through to the end, invite them to start anywhere, picking the specimens they like best--they'll be far more engaged in figuring out what they have if it's the piece they're most curious about. The procedure outlined in ROCKS AND MINERALS first asks you to determine if the rock is igneous, metamorphic or sedimentary and then asks you to categorize it by the size of the grains in the rock. This leads you to a list of possible identifications. You then flip to the indicated pages and compare your sample with the choices offered. Each step is illustrated with photographs that clearly show the features you are being asked to consider.
STEP 3: STORING A COLLECTION
Once all the specimens are identified and marked, you and your children should take the time to find a special place for storing and/or displaying your finds. Not only does this give the children a showcase for their new discoveries, it also inspires everyone in the family to head out for another rock hunt on the next warm, sunny day.
