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Mineral, naturally occurring homogeneous solid with a definite chemical composition and a highly ordered atomic arrangement. Usually formed by inorganic processes, there are several thousand known mineral species, about 100 of which constitute the major mineral components of rocks.
The most common native metals, which are characterized by simple crystal structures, make up three groups: the gold group, consisting of gold, silver, copper, and lead; the platinum group, composed of platinum, palladium, iridium, and osmium; and the iron group, containing iron and nickel-iron.
Carbonate mineral, any member of a family of minerals that contain the carbonate ion, CO32-, as the basic structural and compositional unit. The carbonates are among the most widely distributed minerals in the Earth’s crust. The crystal structure of many carbonate minerals reflects the trigonal.
Mineralogists, or people who study minerals, have identified hundreds of minerals. Some of the most common minerals are metals —for example, gold, silver, copper, and platinum. Diamond, quartz, sulfur, mica, talc, and salt are other well-known minerals.
Rock, in geology, naturally occurring and coherent aggregate of one or more minerals. Such aggregates constitute the basic unit of which the solid Earth is composed and typically form recognizable and mappable volumes. The three major classes of rock are igneous, sedimentary, and metamorphic rock.
Mining, process of extracting useful minerals from the surface of the Earth, including the seas. A mineral, with a few exceptions, is an inorganic substance occurring in nature that has a definite chemical composition and distinctive physical properties or molecular structure.
Silicate mineral, any of a group of silicon-oxygen compounds that are widely distributed throughout much of the solar system. The silicates make up about 95 percent of Earth’s crust and upper mantle, occurring as the major constituents of most igneous rocks.
There exist relatively few minerals with constant composition; notable examples include quartz (SiO 2) and kyanite (Al 2 SiO 5). Minerals of this sort are termed pure substances. Most minerals display considerable variation in the ions that occupy specific atomic sites within their structure.
Accessory minerals present in igneous rocks in minor amounts include monazite, allanite, apatite, garnets, ilmenite, magnetite, titanite, spinel, and zircon. Glass may be a major phase in some volcanic rock but, when present, is usually found in minor amounts.
Mohs hardness, rough measure of the resistance of a smooth surface to scratching or abrasion, expressed in terms of a scale devised (1812) by the German mineralogist Friedrich Mohs. The Mohs hardness of a mineral is determined by observing whether its surface is scratched by a substance of known or.