How Rocks are Formed | The Rock Cycle Explained !!

Rocks are constantly changing on Earth. Most of the rocks today on Earth are only 100 million years old. If we look at certain rocks today and go back some million years, that rock would be in a completely different form and shape. Rocks constantly change their formations and transport around the Earth through a sequence of events involving the formation, alteration, destruction, and reformation as a result of natural processes. Rocks are naturally occurring. They are a solid collection of mineral grains and chemicals. They are formed in different ways and are classified upon the quantity of minerals in them, their chemical composition, and by the ways they were formed. The mantle, crust, and surface of the Earth can be thought of as a giant recycling machine. Rocks are neither created nor destroyed, but redistributed and transformed from one rock type to another. The rock cycle involves the recognition of three main classes of rocks, which are igneous rocks, sedimentary rocks, and metamorphic rocks. Igneous rocks are those types of rocks which are formed when magma or lava cools down. Igneous rocks can be categorized into two types. When magma cools down inside the Earth slowly and slowly, it creates intrusive igneous rocks, and the slow cooling process allows large intrusive crystals to form. But when magma is pushed from the volcanoes during eruptions, they are described as lava, and when that lava cools down, they form extrusive igneous rocks. And because of the fast cooling process of these rocks, they contain a very small amount of crystals in them. Examples of igneous rocks include basalt and granite. These extrusive igneous rocks are then broken down into very small pieces with weathering of rocks by wind, air, water, ice, and gravity, and are transported across the planet. Once enough of these small rocks are gathered and settled together, the bottom layers of these rocks are compressed by gravity and are cemented together, and then they are converted into another kind of rock called sedimentary rock. Sedimentary rocks are formed by sediment that is deposited over time, usually as layers at the bottom of lakes and oceans. This sediment can include minerals, small pieces of plants, or other organic matter. Sedimentary rocks form layers called strata, which can often be seen in exposed cliffs. Examples of sedimentary rocks include limestone, sandstone, mudstone, chalk, and coal. Sedimentary rocks are very soft as well. When we find sedimentary rocks, we can work out what the environment was like when those rocks were formed. However, there is another kind of rock called metamorphic rock. Metamorphic rocks are changed in physical or chemical form from older rocks. All three kinds of rocks may change into metamorphic rocks. Heat and pressure inside earth causes older rocks to change into new ones. Metamorphic rocks can be formed from other metamorphic rocks, and they can form from sedimentary and igneous rocks too. If the igneous rock basalt is exposed to sufficient heat and pressure, it can be transformed into the metamorphic rock called metabasalt. The most common type of metamorphic rock is gneiss, and it forms from granite, which is an igneous rock. Granite has mineral grains of different colors. Sedimentary rocks can transform into metamorphic rocks as well. For example, sandstone becomes quartzite, shale becomes slate, limestone becomes marble. The rock cycle does not go in just one direction. Any given rock can go through any part of the cycle any number of times.