Compression, shearing and tension are the three main types of stresses faced by rocks. In regards to the force of compression, external force acts on the rock to squeeze it until it disintegrates. In case of shearing, the rock is pulled in two opposite directions by force. This ultimately results in the rock breaking down into pieces. Tension is another force that pulls the rock, making it thin in the middle. This way the rock disintegrates as it becomes weaker and weaker in the middle. Most of the rocks present in the earths crust are hugely affected by these three forces.