Igneous rock forms because of melting followed by cooling. Here's why:
1. Igneous rocks are formed when molten magma or lava cools and solidifies. This process can happen deep below the Earth's surface or on the surface during volcanic eruptions.
2. As the molten material cools, it undergoes crystallization, where mineral crystals form as the magma or lava solidifies. The rate of cooling influences the size of the crystals in the rock. Rapid cooling results in smaller crystals, while slow cooling allows for larger crystals to develop.
3. Examples of igneous rocks include granite, basalt, and obsidian. Granite is a common intrusive igneous rock formed from slowly cooled magma beneath the Earth's surface, while basalt is an extrusive igneous rock that forms from rapidly cooled lava on the surface.
In conclusion, igneous rocks are characterized by their formation through the process of melting followed by cooling, which leads to the creation of a wide variety of rock types based on the cooling rate and mineral composition.
