Igneous Rocks Quiz Questions -2

Intrusive igneous rocks are formed below the earth's surface. They are formed when magma cools and solidifies slowly beneath the surface, allowing for the growth of large mineral crystals. This slow cooling process gives intrusive rocks their characteristic coarse-grained texture. Examples of intrusive igneous rocks include granite and diorite.

Extrusive igneous rocks are formed from lava that cools quickly on the Earth's surface. The rapid cooling prevents the crystals from growing large, resulting in small crystal size.

Intrusive igneous rocks are formed when magma cools and solidifies beneath the Earth's surface. Due to the slow cooling process, these rocks have a longer period of time for the crystals to grow, resulting in larger crystal sizes. Therefore, intrusive igneous rocks are characterized by large crystal size.

Mafic minerals are a group of minerals that are rich in magnesium and iron. Pyroxene and olivine are both examples of mafic minerals. Pyroxene is a group of dark-colored minerals that are commonly found in igneous and metamorphic rocks. Olivine is a green mineral that is often found in basaltic rocks. Plagioclase feldspar, muscovite mica, and quartz are not mafic minerals as they do not contain high amounts of magnesium and iron.