calcite dolomite article about calcite dolomite

Effect of calcite and dolomite on crude oil combustion ...

2020-1-1  Calcite and dolomite were obtained from Institute of Geology and Petroleum technologies (Kazan Federal University, Kazan, Russia). The dolomite sample is composed of 91.5% dolomite, 6.0% calcite, 2.2% albite and 0.3% quartz. The calcite sample contains 75% calcite and 25% dolomite. They were crushed before being used for experiments.

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Calcite and dolomite in intrusive carbonatites. II. Trace ...

2015-6-16  The composition of calcite and dolomite from several carbonatite complexes (including a large set of petrographically diverse samples from the Aley complex in Canada) was studied by electron-microprobe analysis and laser-ablation inductively-coupled-plasma mass-spectrometry to identify the extent of substitution of rare-earth and other trace elements in these minerals and the effects of ...

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Retention of phosphorus on calcite and dolomite ...

It is interesting to note that the Mg content in dolomite favors the rapid growth of DCP at phosphorus levels >200 mg L −1. As a result, at pH ≥ 8.0, dolomite shows a stronger capacity for immobilizing phosphorus than does calcite. Dolomite therefore serves as a better phosphorus sink than calcite in calcareous soil environments.

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Dolomite-calcite textures in early carbonatites of the ...

In early calcite carbonatites of the Kovdor ore deposit four morphological types of dolomite are represented. In the first type, dolomite microcrystals occur as lamellae enclosed by optically continuous calcite. In the second, dolomite microcrystals occur as segmented rods, plates and xenomorphic grains, enclosed by optically discontinuous calcite, and in the third, dolomite is represented by ...

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Structure of the (104) surfaces of calcite, dolomite and ...

Atomistic computer simulation methods have been employed to model the structure of the (10 4) surfaces of calcite (CaCO 3), dolomite [CaMg(CO 3) 2] and magnesite (MgCO 3).Our calculations show that, under anhydrous vacuum conditions, calcite undergoes the greatest degree of surface relaxation with rotation and distortion of the carbonate group accompanied by movement of the calcium ion.

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Influence of crystal nucleus and lattice defects on ...

2021-11-13  A higher content of dolomite in the initial rock sample led to greater contact area between dolomite and calcite, allowing more Mg 2+ to diffuse into the calcite lattice and supporting greater dissolution of calcite. However, the addition of a dolomite crystal nucleus must be at the appropriate proportion; in an acidic environment, dolomite ...

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Estimation of visible, near-, and mid-infrared complex ...

2021-1-15  When calcite and dolomite values are compared to other IR studies they generally show good agreement (see Fig. 2a and b). As a result, I rely upon the HEA (1970) dispersion analyses for both optical axes of calcite, magnesite, and dolomite that permit calculation of OCs at IR wavelengths. 4. Derivation of the OCs4.1. VMIR

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Surface–water interactions in the dolomite problem ...

Atomistic computer modelling methods are used to investigate the effect of the strong magnesium–water interaction on the crystal growth of dolomite MgCa(CO 3) 2.We find that the main dolomite cleavage plane under aqueous conditions is less stable than its counterparts in either pure calcite CaCO 3 or magnesite MgCO 3.Molecular dynamics simulations of the incorporation of CaCO 3 and MgCO 3 at ...

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Re: Is this Calcite or Dolomite - mineral-forum

2020-8-1  Physically, calcite is softer than dolomite. Calcite has a hardness of 2.5 - 3, where-as dolomite is 3.5 - 4. Dolomite will scratch calcite, but not the reverse. Also, dolomite is less soluble in cold acids (such as HCl) than calcite. If a bit of it fizzes readily in acid, it

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Application of calcite, Mg‐calcite, and dolomite as Raman ...

2020-5-13  The Raman spectra of calcite, Mg-calcite, and dolomite were measured under ambient and high pressure–temperature (P-T) conditions using a hydrothermal diamond anvil cell, for the purpose of developing new pressure sensors suited for experiments investigating the physicochemical properties of carbonate minerals.By fitting the Raman vibrational frequencies as functions of pressure and ...

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Calcite and dolomite in intrusive carbonatites. II. Trace ...

2015-6-16  The composition of calcite and dolomite from several carbonatite complexes (including a large set of petrographically diverse samples from the Aley complex in Canada) was studied by electron-microprobe analysis and laser-ablation inductively-coupled-plasma mass-spectrometry to identify the extent of substitution of rare-earth and other trace elements in these minerals and the effects of ...

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Retention of phosphorus on calcite and dolomite ...

It is interesting to note that the Mg content in dolomite favors the rapid growth of DCP at phosphorus levels >200 mg L −1. As a result, at pH ≥ 8.0, dolomite shows a stronger capacity for immobilizing phosphorus than does calcite. Dolomite therefore serves as

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Cathodoluminescence in Calcite and Dolomite and Its ...

Most carbonate petrologists consider Mn2+ and Fe2+ to be the only trace elements responsible for cathodoluminescence in carbonates. However, luminescence in carbonates is caused or inhibited by a number of trace elements. The main activators in calcite and dolomite are Mn2+ , Pb2+ and several rare earth elements. For Mn-activated luminescence in these minerals, the main sensitizers are Pb2+and ...

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Self-accelerating volumetric dolomite-for-calcite ...

2020-3-7  Even after 30 dolomite precipitation and calcite dissolution increments, both the modern and Devonian-like seawater-derived evaporative brine solutions are undersaturated with calcite after their final dolomite precipitation and calcite dissolution increments and have final calcite saturation indices of − 0.76 and − 0.19, respectively.

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Structure of the (1014) Surfaces of Calcite, Dolomite, and ...

2000-6-12  @article{osti_759850, title = {Structure of the (1014) Surfaces of Calcite, Dolomite, and Magnesite under Wet and Dry Conditions}, author = {WRIGHT, KATE and CYGAN, RANDALL T and SLATER, BEN}, abstractNote = {Atomistic computer simulation methods have been employed to model the structure of the (10{bar 1}4) surfaces of calcite, dolomite and magnesite.

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Oxygen Isotope Fractionation between Coexisting Calcite ...

Cite this article. WEBER, J. Oxygen Isotope Fractionation between Coexisting Calcite and Dolomite in the Freshwater Upper Carboniferous Freeport Formation.

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The mechanical and microstructural behaviour of calcite ...

The styles and mechanisms of deformation associated with many variably dolomitized limestone shear systems are strongly controlled by strain partitioning between dolomite and calcite. Here, we present experimental results from the deformation of four composite materials designed to address the role of dolomite on the strength of limestone. Composites were synthesized by hot isostatic pressing ...

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Surface–water interactions in the dolomite problem ...

Atomistic computer modelling methods are used to investigate the effect of the strong magnesium–water interaction on the crystal growth of dolomite MgCa(CO 3) 2.We find that the main dolomite cleavage plane under aqueous conditions is less stable than its counterparts in either pure calcite CaCO 3 or magnesite MgCO 3.Molecular dynamics simulations of the incorporation of CaCO 3 and MgCO 3 at ...

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Calcite-Dolomite - UND

2019-9-26  Calcite (or Dolomite) in a Marble. The views above show calcite (or dolomite) in a marble from the Adirondack Mountains, New York. The field of view is about 2 mm across. Minor graphite is also present as long skinny flakes in the carbonate. Most of

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Core level studies of calcite and dolomite Request PDF

Calcite and, to a significantly lesser extent, dolomite are the major carbonate minerals in sedimentary rocks. In modern sediments, aragonite and high-magnesian calcites dominate in shallow water ...

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Cathodoluminescence in Calcite and Dolomite and Its ...

Most carbonate petrologists consider Mn2+ and Fe2+ to be the only trace elements responsible for cathodoluminescence in carbonates. However, luminescence in carbonates is caused or inhibited by a number of trace elements. The main activators in calcite and dolomite are Mn2+ , Pb2+ and several rare earth elements. For Mn-activated luminescence in these minerals, the main sensitizers are Pb2+and ...

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Oxygen Isotope Fractionation between Coexisting Calcite ...

Cite this article. WEBER, J. Oxygen Isotope Fractionation between Coexisting Calcite and Dolomite in the Freshwater Upper Carboniferous Freeport Formation.

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Structure of the (104) surfaces of calcite, dolomite and ...

Atomistic computer simulation methods have been employed to model the structure of the (10 4) surfaces of calcite (CaCO 3), dolomite [CaMg(CO 3) 2] and magnesite (MgCO 3).Our calculations show that, under anhydrous vacuum conditions, calcite undergoes the greatest degree of surface relaxation with rotation and distortion of the carbonate group accompanied by movement of the calcium ion.

Read More

Structure of the (1014) Surfaces of Calcite, Dolomite, and ...

2000-6-12  @article{osti_759850, title = {Structure of the (1014) Surfaces of Calcite, Dolomite, and Magnesite under Wet and Dry Conditions}, author = {WRIGHT, KATE and CYGAN, RANDALL T and SLATER, BEN}, abstractNote = {Atomistic computer simulation methods have been employed to model the structure of the (10{bar 1}4) surfaces of calcite, dolomite and magnesite.

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Petrographic and Geochemical Contrasts Between Calcite ...

The calcite-filled burrows are found close to the paleo-shoreline of the Canadian Shield, whereas the dolomite-filled burrows are found in deeper ramp deposits. In the calcite-filled burrows the parent burrows, each surrounded by a diagenetic halo, are readily apparent, whereas the dolomite-filled burrows are largely devoid of original structures.

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The mechanical and microstructural behaviour of calcite ...

The styles and mechanisms of deformation associated with many variably dolomitized limestone shear systems are strongly controlled by strain partitioning between dolomite and calcite. Here, we present experimental results from the deformation of four composite materials designed to address the role of dolomite on the strength of limestone. Composites were synthesized by hot isostatic pressing ...

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Petrologic and geochemical attributes of calcite ...

Several generations of calcite cementation and dolomite are the result of complex diagenetic changes. Calcite cements include isopachous fibrous, equant drusy mosaic, pendant/meniscus, blocky spar, syntaxial, fibrous, and bladed. These cements formed during early and late diagenetic events; pre- syn- and post exposure in shallow and deeper ...

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The influence of Ca–Mg disorder on the growth of

We performed empirical calculations at 0 K on the (10.4) slabs of dolomite with increasing thickness and different Ca 2+ –Mg 2+ distributions (i.e., different degrees of structural disorder) in the 10.4 layers forming the slab.The energy of the isolated (10.4) dolomite slabs and (10.4) dolomite slabs in epitaxy with the (10.4) calcite slabs was determined.

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