Little Pieces of Earth— Rocks across the Curriculum

by Christy Peterson

xWhen I set out to write this article, I pulled a collection of rocks from the cupboard and set them on my desk. There is a frothy bit of pumice, belched out of some long-ago volcano. Another remnant of the Pacific Northwest’s volcanic past, a thunder egg, sits to the right. There is petrified wood and a couple of fossils—a connection with life long past. And there is a fine-grained, nondescript greenish rock with softened curves that fits so neatly in my left hand, I can imagine myself living long ago and using it to grind grain.

Children become fascinated with rocks at a young age—think of any two-year old you know gathering up gravel in a parking lot! Though their tastes become more sophisticated, this interest often remains well into grade school, making the study of rocks an ideal vehicle for teaching concepts beyond science.

There are many good resources for teaching geology and the rock cycle, some of which I will list at the end of the article, but for this piece, I want to focus more on the cross-curricular potential of rocks. Here are some ideas for extending the study of rocks into other disciplines.


Math and science are companions, and you inevitably will include mathematical concepts in your science unit already. You may be discussing mass, density, displacement, volume, circumference, and even trajectory. Regardless of what you have planned, I encourage you to include a sorting activity. Sorting is a deceptively simple concept usually introduced at the Pre-K level, but behind the plastic manipulatives lies surprisingly sophisticated science. After all, what is taxonomy but sorting? Scientists across the disciplines group objects or living things with similar characteristics together to better understand the world.

Divide students into groups of 3-4 and have them put their rocks* together in the center of the group. Have them sort the rocks based on their own invented criteria (or you can have the group choose how to sort the collection). Depending on the age of your students, encourage more or less sophisticated criteria, but let them come up with the categories. For example, younger students might sort based on color or size; older students might be required to come up with criteria like relative hardness (using the Moh’s scale) or the type of rock it is (igneous, sedimentary, or metamorphic).

*You will need a variety of rocks for this activity. In addition to your own collection, I suggest you invite each student to contribute 2-3 rocks. Make sure you mark them so students can retrieve their treasures at the end of the unit.


What do rocks have to do with history? Plenty, as it turns out, thanks to our tendency to use rocks to mark a moment in time, a sacred space, or even a spot on a map. Think Plymouth Rock and Mt. Rushmore, Uluru and the Black Stone of the Kaaba, Independence Rock and the Rock of Gibraltar.

Here’s an idea to extend your rock study into social studies—with your students, come up with a list of famous rocks. Don’t forget rocks that have been made into something, like Stonehenge and the Washington Monument. Have each student choose a famous rock(s) and make a poster, write an essay, or create a presentation to share with the class.

You can also discuss how the desire for certain kinds of rocks has shaped history. Salt, after all, is a rock, as are gold, silver, and diamonds. Salt has been used as currency. Gold and silver “rushes” shaped the people and boundaries of the American West. Current warfare in Africa has led to a ban in the trade of “conflict diamonds.” Clearly, the desire for certain kinds of rocks drives politics and societies even today.


In the utter silence of a temple,
A cicada’s voice alone
Penetrates the rocks
~Matsuo Basho

A social studies discussion about rocks begins to touch on the fact that humans have a connection with rocks that defies explanation. Yes, we find them beautiful and valuable, but this cannot fully explain the relationship. I suspect our emotional response has something to do with the fact that rocks tie us to the past as nothing else can. They mark places where people lived and died long after they are gone. It is this grounding—this perceived permanence—which inspires poetry and prose.

I recommend starting this portion of your rock study by reading If You Find a Rock, by Peggy Christian, to your class. It is the best book I have found that touches on our emotional connection to rocks. Ask your students if they have a favorite rock. Why do they like it? Is it the color? The shape? Does it remind them of a special event or place?

You can move on to a survey of poems and stories written about rocks. I like to begin with a look at haiku, a poetry form that is simple enough in form for very young students but challenges even the most accomplished poets. I’ve included some links below. There are many “just plain fun” books and poems written about rocks as well, so don’t limit your study to the “highbrow.” Kenn Nesbitt has a very fun poem about pet rocks (also included in the links below).

If you’ve been teaching for a while, I’m sure you have more in your bag of tricks than this article can hope to contain, but I hope you’ve picked up a few tidbits to help you to incorporate rocks across the curriculum. Have fun!

General Books & Links

Science and Math Books & Links

Literature Books & Links

Christy Peterson

Christy Peterson is notorious for shouting “Look, LOOK” when she spots wildlife while riding in a car. Her husband begrudgingly admits that this can sometimes be useful, like when she spotted the grizzly bear in Yellowstone. When she isn’t nearly causing road accidents, she is a freelance writer. She lives in Vancouver, WA with the aforementioned husband, two kids, two dogs, three cats, two guinea pigs, one frog, three lizards, and some fish! She blogs at