Gear Up For A Geology Lesson

Rock hunting can be an enormously gratifying hobby for kids and families. It's an incentive to get outdoors, go to pleasant, out-of-the-way places and learn how the land around you came to look the way it does. Best of all, it enables children to embark on a new collecting adventure.

For a successful rock hunt with your kids, you don't need to come home with museum-quality specimens. The joy of being a rock hound is in the pure thrill of discovery, not necessarily the quality of your finds. Here's how to stage your kids' expedition and identify the rocks they collect. Plus, special games to ensure that your children get the most out of their rock hunt and come home happy.

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Rock Hunt

PROJECT 1:
Find and identify a variety of rocks

GOAL:
To start a rock collection and learn basic geology skills such as using simple tools, identifying appropriate areas to search and correctly identifying rocks and minerals

AGES:
Five to 12

MATERIALS:
• Rock and mineral guide
• A lightweight sledge or "drill" hammer, a half-inch chisel or rock hammer, and a half-inch cold or "pocket" chisel
• Two or three inexpensive screwdrivers
• One hand lens (10X magnification) for each child
• One pair of safety goggles per child
• Hard hats or bike helmets (if you're collecting on cliffs or road cuts)
• Work gloves
• Two sturdy bags for equipment and specimens
• Blank stickers, note pads and pencils
• Newspaper, plastic bags, tissue paper or bubble wrap (for packing specimens)
• A compass and map
• Water, snacks, sunscreen, hat and a first-aid kit

As much as children love picking up rocks here and there, it may take some time for them to develop a high level of enthusiasm for an advanced rock-hunting expedition. Over time, though, they'll get better at spotting interesting rocks and minerals to investigate as well as extracting specimens for our collections, and learning how to go about identifying our samples.

PREP: OUTFITTING YOUR ROCK HOUNDS
The library is a good place to start your research. You'll need to find a good book on rock and mineral hunting in your area and do a little research. Unless you own a big piece of property, you'll also need to make a few phone calls to find a good rock-hunting locale. Try calling either the geology department of a nearby university or the minerals department of a local museum. Be sure to find out if you need permission to gather specimens from the properties (no matter what anyone says, it's illegal to take anything, including rocks, from any national park).

When you've settled on a spot, you and your kids can begin organizing the rock-hunting materials. You can either buy official tools or improvise from your home toolbox. For breaking rocks and prying out samples, rock hunters use a hammer called a geologist's pick (or g-pick), which has a square end for smashing large rock and a pick at the other end for prying and splitting sedimentary rock. You can buy one of these at a rock show or specialty store. You also can do just fine with a standard lightweight sledgehammer, a half-inch cold chisel and a couple of cheap screwdrivers.

While you're at the hardware store, be sure to purchase a pair of safety goggles for each child, regardless of whether or not they'll be working with the hammers and chisels--rock fragments can fly great distances. Also, if you'll be chipping rocks out of a cliff face or road cut, be sure everyone has a helmet. You needn't buy hardhats--bike helmets will work fine.

STEP 1: FINDING A PRIME SPOT
There are a few specific locations that will increase your odds of finding interesting specimens. The road cut is every rock hunter's favorite destination (other fruitful locations are stream beds, hillside ledges and the rock faces of sea cliffs, quarries and mine dumps). The beauty of the road cut, as with quarries, is that the bulldozers and dynamite have already done most of the hard work, uncovering different formations for you. Road-cut exploration, like quarry exploration, requires certain safety precautions, though, especially with children. Before we headed out, I went over the rules with all the children: stay with me, stay off the road, keep your eyes and ears open, and wear your helmet.

STEP 2: USING THE TOOLS
First, let the kids practice cracking open some fallen rocks. When using the lens, hold close to your eye and move the specimen toward you until it comes into focus. If the kids aren't sure how to do this, let them practice on a scrap of newspaper. When the letters are crisp and clear, the kids will know they have them in focus.

In rock-hound jargon, a "hog" is a person who takes more samples than he or she can use, while a "waster" is someone who needlessly busts them up. Kids, particularly those armed for the first time with a rock hammer, need to be warned against hacking away at whatever is in front of them.

Instead, encourage them to break up rocks that are already on the ground. It will also help cut down on overload if you explain to your kids that as they work, they should be careful to number their specimens, enter the date and location on their note pads, and carefully wrap pieces for transport home. Besides slowing the kids down a little, this is a crucial step for anyone starting a collection. It's amazing how easy it is to forget where a rock came from or when it was collected.

STEP 3: ROCKS 101
While you're out in the field, you can begin talking about how the landscape around you came to look the way it does. Don't try to recite the events of the Cretaceous period, just spend some time speculating on how the landscape got its shape. Here are some of the basics:

IGNEOUS ROCKS
are fire rocks (if they know the work ignite, that can help kids hold onto the meaning of igneous), either liquid rock that broke through the earth's surface and then cooled out in the air, or liquid rock that cooled underground and then made its way up toward the surface.

METAMORPHIC ROCKS
have been changed by intense heat or pressure, and are akin to a blueberry muffin where the batter becomes solid and the blueberries lose their shape in the heat of the oven.

SEDIMENTARY ROCKS
are igneous or metamorphic rocks that have shifted from their original positions, becoming layered and stacked. For kids, they're best compared to a laundry basket or a pile of dirty clothes lying on the floor: one item gets deposited on top of another and the bottom layers are the oldest.

MINERALS
are natural solids such as talc, quartz, silver, topaz, sulphur, mercury and diamonds. When one or more minerals combine, they form a rock.

STEP 4: ROCK GAMES
As soon as your kids get the hang of finding and identifying rocks, you can add to the excitement by introducing a few theme hunts. Here are our favorites:

• Ask the kids to find "shape rocks." Kids will get a kick out of finding rocks shaped like button mushrooms or eagles with outspread wings.
• In a stream bed, ask the children to find "rainbow rocks"--ones that contain at least one rainbow color.
• Play "I Spy"--have the kids challenge each other to find a rock with a big pink vein, a dotted rock, a split rock and so on.

Identifying Rocks

PROJECT 2:
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.