Difference between rock and minerals
Answers
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A mineral is a naturally occurring, inorganic solid with a definite chemical composition and a crystalline structure formed by geological processes. A rock is an aggregate of one or more minerals whereas a rock may also include organic remains and mineraloids. Some rocks are predominantly composed of just one mineral.
Mineral
A mineral is a solid formation that occurs naturally in the earth while a rock is a solid combination of more than one mineral formations which is also occurring naturally.
A mineral has a unique chemical composition and is necessarily defined by its crystalline structure and shape. On the other hand, since a rock can be composed of several minerals it is classified according to the process of its formation. A rock can also contain organic remains and mineraloids apart from regular mineral formations. There are some rocks that may include just one mineral formation though.
The commercial value of minerals is immense and rocks are mined to extract these minerals. Such rocks are known as ores and the residue of the rock after the mineral has been extracted is called tailing.
Rock
The classification of rocks also depends on their mineral and chemical composition, texture and the process of formation. Rocks are therefore classified as igneous, sedimentary and metamorphic. A rock cycle defines how one rock form changes to another. For example, a sedimentary rock form is limestone that is composed only of the mineral calcite.
Main rocks on earth contain minerals like magnetite, quartz, feldspar, mica, epidote etc. But more than half of the mineral types classified in geological studies are considered rare. Igneous rocks are formed when molten lava solidifies after a volcanic eruption and is known to be rich in the mineral granite. Sedimentary rocks are formed when deposition of organic matter, chemical precipitates etc takes place. These usually contain minerals like shale, siltstone, sandstone, etc. The metamorphic rocks are formed by the transformation of one rock type to another. No such process is applicable to minerals.
Rocks have great cultural, commercial and social value only because of the mineral present in them. Rocks are also used to establish dates of various civilizations that have existed on earth.