Igneous or Magmatic or Eruptive Rocks: also called volcanic rocks, these rocks form from the solidification of magma. Depending on the original chemical composition of the magma and the time available for crystallization, they are divided into:
- Femic or Mafic Rocks: rich in Iron (Fe), Magnesium (Mg), Manganese (Mn), and poor in silicates
- Felsic or Sialic Rocks: rich in silicates and light elements such as Sodium (Na), Potassium (K), Carbon Dioxide (CO2), and water (H2O)
- Pegmatitic Rocks
- Pneumatolitic Rocks
- Hydrothermal Rocks
