Science
Igneous sedimentary metamorphic.
Definition
The three main types of rocks classified by how they form. Igneous rocks form from cooled magma or lava, sedimentary rocks form from compacted layers of sediment, and metamorphic rocks form when existing rocks are changed by heat and pressure.
Examples
Real-world.
- 1 Granite (igneous) forming slowly underground from cooling magma
- 2 Limestone (sedimentary) forming from accumulated marine shells and calcium carbonate
- 3 Marble (metamorphic) forming when limestone is subjected to intense heat and pressure