Calcite is among the most abundant minerals on earth and plays a central role in many environmental and geochemical processes. Here we used amplitude modulation atomic force microscopy (AFM) operated in a particular regime to visualize single ions close to the (1014) surface of calcite in solution. The results were acquired at equilibrium, in aqueous solution containing different concentrations...

The mixture of EDTA-soluble proteins found in abalone nacre are known to cause the nucleation and growth of aragonite on calcite seed crystals in supersaturated solutions of calcium carbonate. Past atomic force microscope studies of the interaction of these proteins with calcite crystals did not observe this transition because no information about the crystal polymorph on the surface was obtain...

the micromorphology of pedogenic carbonate features in calcareous soils of arid and semiarid regions of kohgilouye province, southwestern iran, has been studied to determine their genesis and distribution in different climatic regions. eight representative pedons (from a total number of 24 pedons) were studied in aridic-ustic (minimum rainfall), ustic and xeric (maximum rainfall) soil moisture ...

As one of the emerging soil improvement techniques, microbial induced calcite precipitation (MICP) can bond soil grains together and improve the engineering properties of soil [1]. bacteria produces urease enzyme can catalyze urea to carbonate and result in calcite precipitation in elevated pH environment. The forms of calcite precipitation around the bacteria limit the availability of oxygen a...

In this study, the sorption behavior of Zn2+ on calcite, kaolinite, and clinoptilolite, in addition to mixtures of calcite with kaolinite and clinoptilolite, was investigated at various loadings and mixture compositions using atomic absorption spectroscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy, X-ray powder diffraction, and Fourier transform infrared techniques. Acc...

Calcite pseudomorphs after ikaite (glendonite) are associated with coldwater depositional systems, including glaciomarine and deepwater settings, as dictated by the limited stability field of ikaite. Ikaite precipitation is favored by elevated alkalinity and dissolved phosphate, conditions encountered commonly in association with organic-rich marine sediments where methane oxidation is occurrin...

We present observations, obtained with ISO-LWS, of the continuum between 50–200 μm of the solar type protostar IRAS 4, in the NGC 1333 complex. The continuum presents an excess, around 95 μm, that we demonstrate must be a dust feature. We compared the 95 μm excess with the calcite feature at 92 μm and find that it fits the observations reasonably well. There may be a further contribution from h...

Calcite-water interactions are important not only in carbon sequestration and the global carbon cycle, but also in contaminant behaviour in calcite-bearing host rock and in many industrial applications. Here we quantify the effect of variations in surface structure on calcite surface reactivity. Firstly, we employ classical Molecular Dynamics simulations of calcite surfaces containing an etch p...

A method to simultaneously determine calcite surface area and content in soils has been developed. The proposed procedure is based on rates of CO2 production upon reaction of soil with buffered acid solutions under controlled conditions. A pressure transducer connected to a chart recorder allows determination of soil calcite dissolution rate, which is directly proportional to calcite surface ar...