Igneous rocks are defined as formations made from solidified lava or magma.
When lava or hot Magma reaches the surface of the earth or a water body it quickly cools down and changes it's from from a hot liquid to a solid rock.
The chemical composition of Igenous rocks can vary depending on their location, cooling time etc.
However, most Igenous rocks contain some or all of the following minerals:
1. Quartz
2. Micas
3. Amphiboles
4. Olivines
5. Pyroxenes
6. Feldspathoids
7. Feldspars