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Carbonate reactions are common in mineral deposits due to CO2-rich mineralising fluids. This study presents the first in-depth, integrated analysis of microstructure and microchemistry of fluid-mediated carbonate reaction …
However, the studies of CO 2 adsorption mentioned above are all based on the ideal calcite environment and do not consider the influence of impurity Mg 2+ because dolomite-MgCa(CO 3) 2 widely exists in natural environment. In other words, the isomorphism phenomenon will often occur in the crystal lattice of calcite, in which Mg 2+ can replace Ca 2+ …
Carbonates are common minerals that make up nearly 20% of sedimentary rocks at the Earth's surface. 1 Limestone, a sedimentary rock composed mainly of calcite (CaCO 3) and dolomite (CaMg(CO 3) 2 ...
How dolomite [CaMg(CO3)2] forms is still underdetermined, despite over a century of efforts. Challenges to synthesizing dolomite at low temperatures have hindered our understanding of sedimentary dolomite formation. Unlike calcium, magnesium's high affinity toward water results in kinetic barriers from hydration shells that prevent anhydrous Ca–Mg …
Dedolomitization can be associated to two processes (Ayora et al. 1998): (1) a one-step or replacement process, involving the dissolution of dolomite coupled with formation of calcite (Evamy 1967) and/or (2) a two-step process involving dissolution of dolomite resulting in secondary pore space, and later precipitation of calcite either during ...
help of calcite-dolomite solvus geothermometer. Two types of marbles, that is, calcite-dolomite marble and quartz-bearing calcite-dolomite marble were selected. Petrographic and scanning electron micro-scope analysis of dolomite samples indicated different grain sizes. X-ray diffraction technique indicated the calcites MgCO3 content up to 7.93 ...
To contribute to filling this gap, this study investigates the interaction between synthetic nanocrystalline calcite and natural dolomite in various solutions (pre-equilibrated …
The mainly products are in abrasive and refractory fields, are widely used in sandblasting and shotblasting; bonded and coated abrasives tools (cutting discs, grinding wheels, drill points, and abrasive sand papers...); polishing; lapping; …
Calcite accommodates strain via grain boundary sliding accommodated by diffusion creep and limited dislocation creep. Dolomite leads to periodic embrittlement within the …
Marble is a granular metamorphic rock, it is derived from limestone or dolomite and It consists of a mass of interlocking grains of calcite or the mineral dolomite. Form of it when limestone buried deep in the older layers of Earth's crust is subjected to heat and pressure from thick layers of overlying sediments.
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 …
The calcite-dolomite solvus in the system CaCO 3 - MgCO 3 was first investigated in 1955 by Harker and Tuttle (1955) and Graf and Goldsmith (1955), and they recognised that the temperature dependence of the amount of MgCO 3 in calcite in equilibrium with dolomite is potentially a precise method of estimating meta- ...
Dolomite is a sedimentary carbonate rock composed primarily of the mineral dolomite (CaMg (CO3)2). It forms through a process known as dolomitization, where limestone (composed mainly of calcite, CaCO3) is …
Motivated by field examples from exhumed seismogenic faults in the Italian Central Apennines, we investigated the frictional and microstructural evolution of gouge mixtures consisting of 50 wt %...
Inelastic x-ray scattering and thermal diffuse scattering experiments on calcite, dolomite, and magnesite show an anomalous dispersion of the transverse acoustic Γ − F branch in calcite and dolomite. We show that the high-pressure transition from calcite to calcite-II is associated with a freezing of the transverse acoustic phonon at the F point of the Brillouin zone.
As the carbonate minerals, calcite is the most stable polymorph of calcium carbonate (CaCO 3).Magnesite is the most common polymorph of magnesium carbonate (MgCO 3), and dolomite is a mineral composed of calcium magnesium carbonate (CaMg(CO 3) 2).In Earth history, the primary precipitates in the existed calcite seas were low-magnesium calcite, …
However, current research on the dissolution characteristics of calcite and dolomite mainly focuses on the macroscopic or batch experiments, although some high-resolution imaging in real-time via atomic force microscopy (AFM) and modeling to reveal the dissolution kinetics and mechanisms have been reported [10], [11], [12].For example, Xu et al. [9] …
Calcite and dolomite both can be opaque, translucent or transparent. In terms of crystallography, calcite and dolomite both can be hexagonal or trigonal. In terms of luster, calcite and dolomite both can be pearly or vitreous. Calcite and dolomite both streak white. Calcite's rarity is similar to dolomite. Calcite's specific gravity overlaps ...
Any dolomite- or calcite-bearing limestone may be metamorphosed during regional metamorphism. The typical result is a massive light-colored marble that may later become exposed in beautiful outcrops. Figures 15.16 and 15.17 show two examples – a marble outcrop on Vancouver Island, Canada, and another on Thassos Island, Greece.
Lines are calculated from experimental data: line 1=calcite+ideal, fully ordered dolomite; line 2=calcite+ordered dolomite with slight Ca-surplus; line 3=calcite+fully disordered protodolomite. The four open circles denote the results of Usdowski (1994), whose up to 7 year-long runs represent the lowest-temperature experimental dolomite ...
Our catalogue of abrasive cleaning products for stone & masonry, including dolomite abrasive 140µ, calcite abrasive 140µ, aluminium silicate abrasive, recycled glass abrasive, walnut shell …
Calcite and dolomite are the two most common minerals in carbonate-bearing faults and shear zones. Motivated by field examples from exhumed seismogenic faults in the Italian Central Apennines, we ...
We report, for the first time, morphological and compositional features of gold mineralization from calcite-dolomite carbonatite of the Guli massif. Gold minerals are represented by natural Au-Ag alloys containing gold (69.64–88.57 wt %) and silver (11.73–30.83 wt %) with low concentrations of copper (up to 0.18 wt %), which predominate ...
Dissolution rates of calcite, dolomite and magnesite were measured at 25, 60, 100 and 150 °C at far from equilibrium conditions in 0.1 M NaCl solutions of pH from 3 to 6 as a function of bicarbonate ion concentration (10 − 5 M ≤ [NaHCO 3] ≤ 0.1 M) and CO 2 partial pressure (1 ≤ pCO 2 ≤ 55 atm). In solutions without initially added NaHCO 3, calcite …
1. Introduction. Calcite and dolomite are frequently encountered in sedimentary ores alongside valuable minerals. Issues arise when these latter are calcium-bearing minerals too (Jiao et al., 2023, Pereira et al., 2023).Froth flotation is usually introduced in the upgrading process of this type of ores, especially in the absence of distinguishing properties between the valuable …
Atomistic simulation methods have been used to calculate and compare the surface structures and energies of the {10 1 4}, {0001}, {10 1 0}, {11 2 0} and {10 1 1} surfaces of calcite and dolomite and to evaluate their equilibrium morphologies. The calcite {10 1 4} and the dolomite {10 1 0} and {11 2 0} surfaces are the most stable crystal planes. Investigation of the …
What is calcite versus dolomite can be seen in the smoothness of the crystal faces on your specimen. Dolomite crystals, because of an unusual internal structure, may have slightly curved crystal faces, while calcite does not. These are some simple tests you can use to determine what is calcite versus dolomite and know the identity of the ...
In this article, a new approach is developed for discrimination of calcite (limestone) and dolomite (dolostone) by utilizing data of Advanced Spaceborne Thermal Emission and Reflection Radiometer ...
The "phenocrysts" are composed of two types of mineral assemblages. The first is a coarse euhedral calcite assemblage in the Jimusar Sag, and the second consists of dolomite, analcime, and pyrite in the Shishugou Sag. The lithological and mineralogical features indicate a hydrothermal origin for these phenocryst-like minerals.
The EDX information of calcite and dolomite rocks before and after aging with solution of oil, asphaltene, and resin in concentration of 1000 ppm in 3 weeks are shown in Fig. 11, Fig. 12, Fig. 13, respectively. Fig. 11 shows EDX analysis for calcite and dolomite rock before and after aging in oil solution. As can be seen, the carbon amount ...
