Written by: on January 9, 2013 @ 10:48 am

Image Source: Pixabay.com

Rocks are one of the many things in life that are easily taken for granted—cursing when we hit them with the garden hoe or taking advantage of them to drive in tent pegs on summer camping trips. They are so common and familiar that they are almost invisible to us as we go about our daily lives. Yet the earth itself and most things in it are made of rocks and minerals. Even living things—including we humans — have minerals within them!

We may not always pay them much attention, but rocks and minerals are far more than just a gray, nondescript background for life – rocks and minerals can be colorful and enormously varied in form. They have exciting biographies— born in fire, carried down mountains by rivers, crushed by glaciers and oceans, compressed and twisted and melted again into yet new forms!

People use rocks and minerals for an amazing variety of purposes, whether it be constructing grand buildings and awe-inspiring works of art, to creating the filaments that light up electric bulbs and the insulation in our homes. From the salt on our food to the gas in our car, we use geology in many ways. The fascinating world of rocks and minerals surrounds us each & every day.

The School of Hard Rocks:

The Earth is made of rock, from the tallest mountains to the floor of the deepest ocean. Thousands of different types of rocks and minerals have been found on Earth. Most rocks at the Earth’s surface are formed from only eight elements (oxygen, silicon, aluminum, iron, magnesium, calcium, potassium, and sodium), but these elements are combined in a number of ways to make rocks that are very different.

Rocks are continually changing. Wind and water wear them down and carry bits of rock away; the tiny particles accumulate in a lake or ocean and harden into rock again. The oldest rock that has ever been found is more than 3.9 billion years old. The Earth itself is at least 4.5 billion years old, but rocks from the beginning of Earth’s history have changed so much from their original form that they have become new kinds of rock. By studying how rocks form and change, scientists have built a solid understanding of the Earth we live on and its long history.

We can’t journey back in time or to the center of the earth, but these rocks give us important clues to what’s been happening over the past 4.6 billion years of the earth’s existence, and what’s still going on miles below our feet. The earth’s outer crust is composed of tectonic plates – pieces of crust –which move slowly but constantly over the lower layers. Where two plates collide, the edges are pushed up into mountains. If an opening is created where they collide or where they part, hot molten magma from deep below can be forced out in a volcano. Where stress builds up from the grinding of two plates against each other, earthquakes can result.

Want to see a small-scale example for yourself? Gently crack a hard-boiled egg all over and manipulate the shell without removing it. In some places it will buckle, in others it will part and expose what lies beneath. If this inspires your scientific curiosity, it’s time to get out of your kitchen! Head out to a quarry or nature preserve to look for some real rock samples. If you’re lucky, you may even find some fossils.

Sound like a glorified scavenger hunt? In a way, it is, but what you’re hunting is the answer to the ultimate question: what happened? Why are the rocks you find where they are – were they carried by a moving glacier or deposited by a river? Why have the fossils of oceanic fish been found on mountaintops? Why is there volcanic rock inMassachusetts? The rocks you find are just the tip of the iceberg.

Ready to become the next Indiana Stones?

Geologists are detectives who use rocks to figure out what forces shaped the earth and how the world will change in years to come. Rock collecting is the perfect way to learn about our planet and the way it works: the movement that placed rocks where you find them, the evolution evident in fossil records, the minerals that are the building blocks of our world. It’s a great hobby; it’s cheap, it’s easy to get started, and kids learn about chemistry, physics and biology while doing what they do best – running around outside and digging in the dirt.

There are three types of rocks: igneous (or volcanic) rocks such as obsidian and granite, created when molten magma from below the earth’s surface cools and hardens; sedimentary rocks such as limestone and sandstone, created when bits of other rocks get smushed together over time; and metamorphic rocks like marble or slate, created when igneous or sedimentary rocks are subjected to great heat or pressure, changing the mineral content.

No matter your age, rock collecting is a hobby that sparks curiosity. Rock collections are a great way to introduce geology to children. From there, they can only learn more and more about the fascinating Earth. Besides, what kid doesn’t love to dig? Geology is definitely a hobby that the entire family can enjoy, together! To get started, you’ll need a basic book with color photos of different rock species, good climbing shoes, baggies, a small hammer for prying bits loose and a notebook. Write up each find – where you found it, what you think it is – and bag separately.

 Then, rock on!

Dig up some more FUN science with these rockin’ resources:

  • The United States Geological Society has a fantastic article about rock collections. Get even more resources from the US Geological Survey: http://education.usgs.gov/
  • Planetary Geology is the study of rocks & space. Check out this great site from NASA on one of science’s fastest growing fields!
  • Paleoportal is a great site for both students AND teachers. It features links to fossil galleries, geology careers, fossil collections, paleontologists, and geologic history for each state.
  • The Mineral Information Institute has a wonderful list of common minerals and their uses. 
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