Rocks and Minerals
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There are three types of rocks; Igneous, Metamorphic, and Sedimentary Rock. The texture of any type of rock change when its surroundings change. Igneous Rock begins as magma, which is formed when rock is heated, when pressure is released, or when rock changes composition. When magma cools enough, it solidifies to form igneous rock. When it comes to Igneous rock, the color determines how dense they are and what elements are in them. A light colored igneous rock, or Felsic Rock, is less dense than the dark colored rock are and have the elements aluminum, potassium, silicon, and sodium. The dark colored Igneous rocks, also called Mafic Rocks, are much more dense than the light colored igneous rocks and are rich in calcium, iron, and magnesium, but is poor in silicon. Igneous rock has two types of textures, which are course grained and fined grained. Fined grained igneous rock contains little to no crystals because the rock cools rapidly, leaving the crystals little time to grow. The course grained igneous rocks get their hard texture by the crystals having a longer period of time to grow before the rock cools. Sedimentary Rock forms when the mineral and rock fragments from erosion form in to rock. This forms at or near the earth's surface, without using heat or pressure that are involve in the making of Metamorphic and Igneous rock. The Metamorphic rock means change in Greek, which is a perfect description for this type of rock. If the temperature or pressure of the new environment is not the same as form the other environment, in which the rock formed, it will undergo metamorphism. This process occurs at 50-1,000 degrees Celsius, but some can take place higher than 1,000 degrees. At these temperatures, most rock would, but metamorphic rock does not. The metamorphic change mostly occurs at depths greater than 2km. There are two types of Metamorphism, contact and regional. Regional Metamorphism occurs when pressure builds up in a rock hat is buried deep below other rock formations or when large pieces of the earth's crust collide with each other. The increased pressure and pressure of this process causes rock to become deformed and chemically changed.Regional Metamorphism occurs over thousands of cubic kilometers deep within the Earth's crust. Contact metamorphism is when magma moves through the earth's crust and gets heated by surrounding rock then changes into other minerals. The biggest change is where magma comes direct contact with the surrounding rock. the effect of this heat on rock gradually decreases as the rock's distance form the magma increases and as temperature decreases. Contact metamorphism occurs near igneous intrusions.
This is an Igneous Rock example.
This is a Sedimentary Rock example.
This is a Metamorphic Rock example.