What Is The Meaning Of Igneous?
The word igneous comes from the Latin word ‘ignis’ which means ‘fire’. Igneous rocks are therefore, those rocks that are formed as a result of cooling of the magma (molten lava). There are two types of igneous rocks: Plutonic and volcanic, or instrusive and extrusive rocks respectively. Plutonic rocks form below the surface of the ground and volcanic rocks form above the surface. A great proportion of the igneous rocks in plutonic. There are about 700 types of igneous rocks in total and about 95% of the earth’s surface is made of igneous rock.
