calcite
cal·cite
C0028000 (kăl′sīt′)calcite
(ˈkælsaɪt)cal•cite
(ˈkæl saɪt)n.
cal·cite
(kăl′sīt′)| Noun | 1. |  calcite - a common mineral consisting of crystallized calcium carbonate; a major constituent of limestone |
| 单词 | calcite | |||||||||||||||
| 释义 | calcitecal·citeC0028000 (kăl′sīt′)calcite(ˈkælsaɪt)cal•cite(ˈkæl saɪt)n. cal·cite(kăl′sīt′)
calcitecalcite(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 sparIceland 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 limestonelimestone, 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. , marblemarble, 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. , chalkchalk, 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 foraminiferans. ..... Click the link for more information. , marlmarl 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 stalagmitestalactite and stalagmite , mineral forms often found in caves; sometimes collectively called dripstone. A stalactite is an icicle-shaped mass of calcite attached to the roof of a limestone cavern. ..... Click the link for more information. formations, travertinetravertine , form of massive calcium carbonate, CaCO3, resulting from deposition by springs or rivers. It is often beautifully colored and banded as a result of the presence of iron compounds or other (e.g., organic) impurities. ..... Click the link for more information. , and Oriental alabasteralabaster, 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 evaporating ..... 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 smeltingsmelting, 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(calcareous spar), a mineral with chemical composition CaCO3, containing 56 percent CaO and 44 percent CO2 and frequently Mg, Fe, Mn (up to 8 percent) as well as Zn, Co, Sr, and Ba. Calcite crystallizes in the trigonal system. It exists in the form of crystals with various habits—rhombohedral, scalenohedral, prismatic, or tabular—as well as in the form of stalactites and solid, granular, and earthy masses (chalk). The Ca and C atoms in the calcite structure are arranged at the lattice points of the rhombohedral lattices as though pushed into one another. The O atoms are in groups of three around each C atom and lie in the same plane. Calcite is brittle and exhibits perfect cleavage on the rhombohedron [1011]. Twins are a characteristic feature. Calcite crystals exhibit a high birefringence, and many are strongly fluorescent. Calcite’s hardness on the mineralogical scale is 3 and its density, 2, 720-2, 800 kg/m3. When heated, calcite decomposes at a temperature of 825°C; it is readily soluble in acids. Calcite is one of the most widely distributed minerals in the earth’s crust, particularly among the hydrothermal formations in contact metasomatic deposits and in amygdaloids and geodes of igneous rocks. It is sometimes formed under magmatogenic conditions, producing carbonatites. Calcite precipitates from hot calcareous springs in the form of tufa (travertine). Enormous masses of calcite are formed as deposits in ocean basins, partly by biogenesis. Calcite appears as the main constituent of limestone, marble, and other sedimentary and metamorphic rocks widely used as construction and facing materials. Pure and transparent varieties of calcite—for example, Icelandic spar—are used in the optics industry. REFERENCESOpticheskie materialy dlia infrakrasnoi tekhniki.Moscow, 1965.“Kal’tsit.” In Fizicheskii entsiklopedicheskii slovar’, vol. 2. Moscow, 1962. Kostov, I. Mineralogiia. Moscow, 1971. (Translated from English.) M. D. DORFMAN and M. O. KLIIA calcite[′kal‚sīt]calcitecalcitecalcitecalcium carbonate(kal-see-um kar-bo-nate) calciumcarbonate,Alka-Mints(trade name),Amitone(trade name),Apo-Cal(trade name),BioCal(trade name),Calcarb(trade name),Calci-Chew(trade name),Calciday(trade name),Calcilac(trade name),Calci-Mix(trade name),Calcite(trade name),Calglycine(trade name),Cal-Plus(trade name),Calsan(trade name),Caltrate(trade name),Chooz(trade name),Dicarbosil(trade name),Equilet(trade name),Gencalc(trade name),Liqui-Cal(trade name),Liquid Cal-600(trade name),Maalox Antacid Caplets(trade name),Mallamint(trade name),Mylanta Lozenges(trade name),Nephro-Calci(trade name),Nu-Cal(trade name),Os-Cal(trade name),Oysco(trade name),Oyst-Cal(trade name),Oystercal(trade name),Rolaids Calcium Rich(trade name),Surpass(trade name),Surpass Extra Strength(trade name),Titralac(trade name),Tums(trade name),Tums E-X(trade name)ClassificationTherapeutic: mineral electrolyte replacements supplementsIndicationsActionTherapeutic effectsPharmacokineticsTime/action profile (effects on serum calcium)
Contraindications/PrecautionsAdverse Reactions/Side EffectsCentral nervous system
Cardiovascular
Gastrointestinal
Genitourinary
InteractionsDrug-Drug interactionHypercalcemia increases the risk of digoxin toxicity.Chronic use with antacids in renal insufficiency may lead to milk-alkali syndrome.Ingestion by mouth decreases the absorption of orally administered tetracyclines, fluoroquinolones, phenytoin, and iron salts.Excessive amounts may decrease the effects of calcium channel blockers.Decreases absorption of etidronate and risedronate (do not take within 2 hr of calcium supplements).May decrease the effectiveness of atenolol.Concurrent use with diuretics (thiazide) may result in hypercalcemia.May decrease the ability of sodium polystyrene sulfonate to decrease serum potassium.Cereals, spinach, or rhubarb may decrease the absorption of calcium supplements.Calcium acetate should not be given concurrently with other calcium supplements.Route/Dosage1 gram of calcium carbonate contains 400 mg elemental calcium (20 mEq calcium). Doses expressed in terms of elemental calcium.AvailabilityNursing implicationsNursing assessment
Potential Nursing DiagnosesImbalanced nutrition: less than body requirements (Indications)Risk for injury, related to osteoporosis or electrolyte imbalance (Indications) Implementation
Patient/Family Teaching
Evaluation/Desired Outcomes
cal·cite(kal'sīt),See also: calcium carbonate. cal·cite(kal'sīt)calcite
Words related to calcite
|
|||||||||||||||
| 随便看 |
|
英语词典包含2567994条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。