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Mineral symbols (text abbreviations) are used to abbreviate mineral groups, subgroups, and species, just as lettered symbols are used for the chemical elements.. The first set of commonly used mineral symbols was published in 1983 and covered the common rock-forming minerals using 192 two- or three-lettered symbols. [1]
Basalt (UK: / ˈ b æ s ɒ l t,-ɔː l t,-əl t /; [1] [2] US: / b ə ˈ s ɔː l t, ˈ b eɪ s ɔː l t /) [3] is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon.
Basalt columns seen on Porto Santo Island, Portugal. Columnar jointing of volcanic rocks exists in many places on Earth. Perhaps the most famous basalt lava flow in the world is the Giant's Causeway in Northern Ireland, in which the vertical joints form polygonal columns and give the impression of having been artificially constructed.
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The following is a list of rock types recognized by geologists. There is no agreed number of specific types of rock. Any unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics can describe a rock type. Additionally, different classification systems exist for each major type of rock. [1]
Monolith with bull, fox, and crane in low relief at Göbekli Tepe. The density of most stone is between 2 and 3 tons per cubic meter. Basalt weighs about 2.8 to 3.0 tons per cubic meter; granite averages about 2.75 metric tons per cubic meter; limestone, 2.7 metric tons per cubic meter; sandstone or marble, 2.5 tons per cubic meter.
A major use for basalt is crushed rock for road and housing construction in concrete, macadam, and paving stones. Because of its insensitivity to chemical influences, resistance to mechanical stress, high dry relative density, frost resistance, and seawater resistance, trap rock is used as ballast for railroad track bed and hydraulic ...