What's so magic about rocks

Rocks carry the stories of our planet

Scattered across landscapes, from mountains to riverbeds, carved by water and wind, sometimes hiding in the depth of the Earth waiting to be uncovered. Rocks carry the tales of our planet transformations, and the stories held within them have no end.

Our planet is nearly 8,078 miles across. It has a thin skin of water, in oceans, lakes and rivers, and an even thinner living skin of soil and vegetation, with an atmosphere above. But Earth is nearly all rock, from which the water, air, soil and life have all emerged, and on which they are utterly dependent.

Essentially, rocks are the foundation of our lives.*

How are rocks formed

Simply put, a rock is a naturally formed, non-living earth material made of one or more minerals. The mineral composition determines the different colours and textures that we get to admire.

However - and this is when is starts getting really magic - that’s not always the case. Rocks containing the same minerals, can have a different texture because they have different histories. For example, a rock might have very visible visible grains and a rough texture because it originated from magma and cooled slowly underground. A rock that cooled rapidly from a very similar magma that erupted onto Earth’s surface will look and feel entirely different.

Never ending transformation

As we know, rocks change as a result of natural processes - water, wind, ice, heat and pressure amongst others. Most changes happen very slowly; many take place below the Earth’s surface, so we may not even notice the changes. Although we may not see these changes, rocks are constantly changing in a natural, never-ending cycle.

As James Hutton, an eighteenth century scientist often called the “Father of Geology” described it, the geologic process has “no [sign] of a beginning, and no prospect of an end.”

The processes involved in the rock cycle often take place over millions of years. So on the scale of a human lifetime, rocks appear to be solid and unchanging, but change is always taking place.

Rocks are endlessly fascinating with their infinite variety and richness. Through them we can learn so much about our planet Earth but also the area in which we live.

When my children were little they loved playing with the rocks at a boulder beach. We learned that those black basalt rocks were the result of lava flowing out of a huge volcano not far from where we lived. That ancient volcano no longer exists, but we could still feel its presence through those giant boulders.

Rocks can feel so familiar we almost don't pay attention to them - but they tell extraordinary and incredibly fascinating stories of our past, present and future.

If you sense in your child a fascination with rocks and geology, take a look at some of the resources listed below, or simply use rocks as loose parts to play with!

Each of the pebbles on a beach or in a river is a rock sample that contains clues to the way in which it formed – a history that can stretch back millions or even billions of years.

Dig deeper

These are some wonderful resources to help children understand the world of rocks:

Every Rock Tells A Story - a great classroom and homeschooling lesson plan and resources produced by Harvard-Smithsonian Center for Astrophysics.

Learn How to Classify Rocks - Rock classification activity sheet created by the Australian Museum