There are three great categories of rocks; the igneous, sedimentary and metamorphic. Most of the time, they are very simple to distinguish and tell apart. They are actually connected in the endless rock cycle, moving from one form to another. Besides, they also change their shape, texture and even the chemical composition along the way.
Igneous rocks are formed from molten rocks material, which are called as magma. These magma consists of thick, fluid masses of very hot elements and compounds. All around the world, the types of igneous rocks vary. However, the similarity that all of them has is they were once melted and undergo cooling down process. They were formed by the cooling and the crystallization of a melt.
Igneous rocks formed at four…show more content… The most common chemical sedimentary rock is limestone, which is a biochemical product of calcium carbonate created by the parts of dead creatures. Approximately, three-quarters of the Earth’s bedrock on the continents is sedimentary.
Metamorphic rock, which comes from the Greek to ‘change form’, is formed by applying great pressure and temperature to existing rock, converting it into a new distinct type of rock. Be it igneous rocks, sedimentary rocks or other metamorphic rocks can still be modified into another metamorphic rocks.
Metamorphic rocks are usually created when they come under extreme pressure such as under many thousands of feet of bedrock or through being crushed at the junction of the tectonic plates. Metamorphic rocks are harder than the other types of rock, so they are more resistant to weathering and erosion. Rock always converts into the same type of metamorphic rock. Meanwhile, sedimentary rocks can become metamorphic rocks if the thousands of feet of sediments above them apply enough heat and pressure to further change the structure of the sedimentary rock. For example, the sedimentary rock limestone and shale can become marble and slate, respectively, when