Calcium carbonate Aragonite

Calcium carbonate Aragonite CaC03 Low temperature scale. 

It is of interest that two thermodynamically unstable forms of calcium carbonate, aragonite and vaterite. are found in living organisms as well as the more stable calcite. There appears to be no simple explanation for the distribution of the different forms in the various species. 

Acute scalcntihcdral crystals are sometimes referred to as dogtooth spar. Calcite represents the stable form of calcium carbonate aragonite will go over to calcite at 470 C (K78=F. Calcite is a common constituent of sedimentary rocks, as a vein mineral, and as deposits from hot springs and in eaves as stalactites and stalagmites. 

CHFCIBr[g] FLUOROCHLOROBROMOMETHANE (GAS) 373 CaC03[A] CALCIUM CARBONATE (ARAGONITE) 424... 

Calcium carbonate (aragonite) CaC03 471-34-1 100.087 wh orth cry or powder trans calcite 450 2.930 0.00066 s dil acid... 

Quite original is the attempt to obtain porous materials, for example, from crystalline calcium carbonate (aragonite) similar to the natural material chalk of a certain porosity [192]. Another attempt was made to synthesize macro-porous aragonite with a structure similar to the cocco-spheres of certain marine algae [295]. For this purpose, oil-water-surfactant microemulsions supersaturated with calcium bicarbonate were obtained. The pore size was determined by the water and oil concentration ratio. Microemulsions were applied on the substrate of micrometersized polystyrene beads. Hollow spherical shells of finished structure were produced as a result of a rapid mineralisation. The authors suggest that such materials could gain widespread use in materitils chemistry. 

Calcium Carbonates Aragonite (from biogenic sources)... 

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