Rock Around the World

Rock Around The World

What Are Rocks?

Rocks are combinations of one or more minerals that we find in nature.

For example:

  • Limestone is composed of only one mineral – calcite
  • Basalt is commonly composed of three minerals – feldspar, pyroxene, and olivine
  • Granite is commonly composed of five minerals – two kinds of feldspar, mica, amphibole, and quartz

Just like minerals, there are many different kinds of rocks. Geologists group rocks into three different categories; igneous, sedimentary, and metamorphic.

  • Igneous rockIgneous rocks form from magma or lava
  • Sedimentary rockSedimentary rocks form from pieces of other rocks or are formed by minerals being precipitated from water
  • Metamorphic rockMetamorphic rocks form by recrystallizing the minerals in a rock under high pressures or temperatures
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Igneous Rocks