Basic Geology Facts
There are three categories of rocks: sedimentary, igneous, and metamorphic.
Sedimentary
Sedimentary rock is formed by the compression of particles of other rocks and the remains of organisms.
Igneous
When magma or lava cools and solidifies, igneous rock is formed.
Metamorphic
Metamorphic rock, as the name suggests, is rock undergoing some sort of metamorphisis, oftentimes high pressures and temperatures.
Minerals
Minerals form the basis of all rocks and are formed under a complex process involving pressure and/or evaporation that oftentimes takes place over millions of years.