Key learning points

1. Components of rocks, such as sand, fossils, shells, crystals, help to indicate how those rocks formed and their age.
2. Rocks contain grains which can be round or interlocking.
3. Some rocks contain crystals that point in many directions while others are aligned.
4. Rock types and textures provide insights into geological processes and Earth's history.

Keywords

• Grain - Grains are the individual pieces that make up a rock.

• Minerals - A mineral is an element or compound with a crystal-like structure. They are the 'building blocks' of rocks.

• Textures - The texture of a rock describes the size and shape of its grains. It also describes how the grains are arranged in the rock.

• Crystals - A crystal is a solid whose particles have a highly ordered arrangement. They often have a regular shape.

• Interlocking - Interlocking describes grains which lock together like a "mosaic". Interlocking grains don't have gaps between them.

Common misconception