Rock, a naturally occurring substance can be seen all around you. No matter where you live, rock is always present near you in one form or another. You will find them in your yard, inside the house, street, etc. Things like chalk, pencil lead, statues, glass, bricks, sandpaper, marble, volcanoes are all rocks. Rock is an important factor in the production of washing machines, airplanes, video games, jewelry, cars and even in the construction of houses. It is not always in the solid form; the mud and sand are also a form of rock.
Some Important Facts
A Rock is composed of one or more mineral or mineral like substances. They are never uniform in size and color. It takes about thousands of years in the formation of rocks. Some of the interesting facts are.
Rocks are entitled to a continuous cycle of change, which takes thousands of years to transform from one form to another.
The rock in the melted form inside the earth is called magma and when it is extruded on the earth’s surface, it is referred as lava. The magma is composed of the atoms and molecules of the melted mineral.
When the lava cools down, the solid structure formed is called igneous rocks. Climate, river or other factors erode the igneous rock over the time to form sedimentary rocks.
This sedimentary rock is covered by deposits of other rock crystals, which form layers inside the crust. The pressure and heat transform that mass into a metamorphic rock. The earth’s crust is full of rocks, and scientific research proves that even the earth space has the presence of rocks called Meteorites.
The top part of the earth’s crust is composed of about 95% igneous rock.
The name “igneous” is derived from a word in the Latin Language “Ignis”, meaning “of fire”.
Ores derived are actually rocks that consist of minerals made up of precious metals like silver and gold.
Sedimentary rocks can be often found under the lake or ocean.
Marble is a type of metamorphic rock which is made of a sedimentary rock called as limestone.
Granulite is a metamorphic rock made out of basalt, an igneous rock.
The meaning of the word “metamorphism” itself means “change in the form”, as all the metamorphic rocks are evolved from some other type of rocks.
Basalt is the most common rock found on the earth and there are around 700 different types of igneous rocks.
An unusual type of rock, known as Pumice is a lightweight rock formed out of the bubbles of molten rocks emerged from the volcano. This bubble immediately cools down and loses pressure, to form this rock.
Many sedimentary rocks undergo changes over the time to evolve as a different rock. For example, Quartzite is a metamorphic rock derived from the sedimentary rock sandstone.
Obsidian rock is also referred as “nature’s glass” as it possesses a glassy appearance. About 70% of this rock is made up of silica.
Limestone is a sedimentary rock which is considered as an organic rock due to the composition of marine fossils.
Metamorphic rocks have many layers that can be easily spilt. Slate is such a metamorphic rock which is often spilt to transform into thin and durable tiles for roofing.
The layers found in the sedimentary rock are known as strata.