Understanding basic rock types gives you more ideas on how each type of rock is formed and this is a good basic for understanding geology.
Rocks can be classified into three main types which are igneous rocks, sedimentary rocks and metamorphic rocks. Figure 1 shows the relationship between the three main rock types.
Figure 1 – Rock Cycle
(Ref Image: http://www.geolsoc.org.uk/ks3/webdav/site/GSL/shared/images/education_and_careers/RockCycle/Rock%20Cycle%20all%20labels.jpg)
Igneous rocks are the most abundant type of rock on the Earth because it makes up about 70% of all rocks. Minerals such as quartz, plagioclase feldspar, pyroxene and olivine are important types of igneous rocks. Figure 3 illustrates minerals found in common igneous rocks.
Figure 2 – Minerals in Common Igneous Rocks.
(Ref Image: https://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Mineralogy_igneous_rocks_EN.svg/640px-Mineralogy_igneous_rocks_EN.svg.png) Continue reading