Rocks and soil


It is by no means necessary to be a geological expert to implement a worthwhile study of rocks and soil at primary school level. Rocks and soil are not difficult to collect, and are a very good vehicle for outdoor activities while at camp or on excursions, collecting and classifying, or making rocks in the classroom.

Students can be fascinated by rocks and soil. A simple rock collection, showing a variety of shapes, sizes, colours and textures, is a good resource. Rocks and soil can be collected during trips to the country, at building sites around the city, or in the back garden.

Mining and metals are very closely related to rocks and soils as a topic. We have included some interesting activities that could be covered under the topics of rocks, soil and mining.

Key concepts of rocks and soil

The activities in this topic are designed to explore the following key concepts:

Early years

  • Earth is covered with rocks, soil, water and ice.
  • Rocks can vary in shape, texture and mass.
  • Rocks can be a single colour or contain many colours.
  • Some rocks contain fossils.
  • Humans make rocks to help them live more easily.
  • Rocks slowly change by wearing away.
  • Crumbled rocks form part of soil.
  • Some rocks are harder than others.

Middle years

  • Rock layers are located under soil, water and ice.
  • Natural rocks are made in many different ways.
  • Rocks that we find at a particular place may have been made elsewhere.
  • Some natural rocks became solid very quickly, while others took a long time to become solid.
  • Rocks are made of minerals.
  • Rocks can be made of one or more minerals.
  • Minerals can form crystals.
  • Crystals can have straight edges and flat slides.
  • Some rocks act as magnets.
  • Some rocks are conductors of electricity.
  • Soils are produced, in part, from the weathering of rocks.
  • Soil can be made up of organic (animal and plant) material, inorganic (grains of rock) components, and water.
  • Eroded rock material can be deposited in layers to form sedimentary rocks, such as sandstone, limestone and mudstone.
  • Igneous rocks, such as pumice and granite, are formed by magma from inside the Earth rising to the surface and cooling.
  • Sedimentary and igneous rocks that are subject to heat and pressure form metamorphic rocks, such as marble, quartzite and slate.
  • Minerals are constituents of rocks.
  • Some minerals (e.g. gold and diamonds) are highly valued by humans.
  • The ornamental use of rocks is determined by their colour, mineral content and markings.
  • The varying hardness of rock is an important factor in its usage.
  • Humans’ knowledge of rock formation helps them to find oil and precious stones (e.g. gold, opal, emeralds, etcetera).

Students’ alternative conceptions of rocks and soil

Research into students’ ideas about this topic has identified the following non-scientific ideas:

  • Pebbles and stones are thought of as ‘not rocks’.
  • All rocks are thought to be hard.
  • Rocks stay the same for ever.
  • Rocks must be heavy.
  • Soil must have always been in its present form.
  • Earth is molten, except for its crust.