calcite (kăl`sīt), very widely distributed mineral, commonly white or colorless, but appearing in a great variety of colors owing to impurities. Chemically it is calcium carbonate, CaCO₃, but it frequently contains manganese, iron, or magnesium in place of the calcium. It crystallizes in the hexagonal system, its crystals being characterized by highly perfect cleavage. Calcite also occurs in a number of massive forms, in which it may be coarsely to finely granular (as in marble), compact (as in limestone), powdery (as in chalk), or fibrous. One crystalline form, called dogtooth spar because of its dogtooth appearance, exhibits faces of perfect scalene triangles. Another form, satin spar, is finely fibrous and has a satin luster. Iceland spar Iceland spar, colorless variety of crystallized calcite , characterized by its properties of transparency and double refraction. It is used chiefly in the manufacture of Nicol prisms , which are essential parts of polarizing microscopes and other optical instruments.
..... Click the link for more information. is clear, transparent calcite. Other important forms of the mineral are limestone limestone, sedimentary rock wholly or in large part composed of calcium carbonate. It is ordinarily white but may be colored by impurities, iron oxide making it brown, yellow, or red and carbon making it blue, black, or gray. The texture varies from coarse to fine.
..... Click the link for more information. , marble marble, metamorphic rock composed wholly or in large part of calcite or dolomite crystals, the crystalline texture being the result of metamorphism of limestone by heat and pressure.
..... Click the link for more information. , chalk chalk, mineral of calcium carbonate , similar in composition to limestone, but softer. It is characteristically a marine formation and sometimes occurs in great thickness; the chief constituents of these chalk deposits are the shells of minute animals called
..... Click the link for more information. , marl marl or bog lime, soil, essentially clay mixed with carbonate of lime, highly valued as a dressing or fertilizer. It crumbles rapidly and easily. Marl in which the lime is in the form of invertebrate shells is called shell marl.
..... Click the link for more information. , stalactite and stalagmite stalactite (stəlăk`tīt) and stalagmite
..... Click the link for more information. formations, travertine travertine (trăv`ərtĭn, –tēn), form of massive calcium carbonate, CaCO₃
..... Click the link for more information. , and Oriental alabaster alabaster, fine-grained, massive, translucent variety of gypsum , a hydrous calcium sulfate. It is pure white or streaked with reddish brown. Alabaster, like all other forms of gypsum, forms by the evaporation of bedded deposits that are precipitated mainly from
..... Click the link for more information. . Millions of tons of calcite, in the form of limestone and marble, are mined annually. Besides its use as a building stone, it is the raw material for quicklime and cement, and is used extensively as a flux in smelting smelting, in metallurgy, any process of melting or fusion, especially to extract a metal from its ore. Smelting processes vary in detail depending on the nature of the ore and the metal involved, but they are typified in the use of the blast furnace .
..... Click the link for more information. and as a soil conditioner.

calcite

Most common form of natural calcium carbonate (CaCO₃), a widely distributed mineral known for the beautiful development and great variety of its crystals. It occurs in stalagmites and stalactites and forms the structure of coral reefs. Calcite is the most important mineral in limestones and marbles used in the building, steel, chemical, and glass industries. Transparent crystals are called Iceland spar.

calcite (redirected from calcitic)

calcite

calcite
(redirected from calcitic)