Rocks, part 1

A natural solid made of one or more minerals.

Rocks are generally a mixture of these.

• conglomerates

• minerals

• salts

• sediments

The classification of rocks depends on...

• where they are found

• their size

• their hardness

• how they form

Rocks formed when melted rocks cool.

• igneous

• sedimentary

• metamorphic

If these rocks form underground, they have large crystals.

• sedimentary

• igneous

• metamorphic

If these rocks form on Earth's surface, they have small or no crystals.

• sedimentary

• metamorphic

• igneous

The most common type of igneous rock. They form above ground and have small crystals.

• basalt

• gabbro

• pumice

• obsidian

This igneous rock is made of the same minerals as basalt, but it forms below ground and has big crystals.

• basalt

• gabbro

• pumice

• obsidian

This igneous rock has a lot of air spaces and is very light.

• basalt

• gabbro

• pumice

• obsidian

This igneous rock is also called volcanic glass.

• basalt

• gabbro

• pumice

• obsidian