Calcium carbonate, analysis aragonite

Klaproth found that precipitated alumina is soluble in caustic potash(i789). He proved by analysis that anhydrite (then called muriacite) is calcium sulphate free from water and that calcite and aragonite are two different crystalline forms of calcium carbonate and confirmed that bitter spar (dolomite) is a compound of calcium and magnesium carbonates. 

X-ray diffraction analysis of the products of the benefici-ation of Dow-Colony shale is shown in Table I. It is clear that the oleophilic extract (pellets) retains or concentrates the calcium and magnesium carbonates (dolomite, calcite, aragonite), particularly the dolomite. The hydrophilic gangue consists mainly of feldspar and quartz. Since silica, silicates and Ca/Ca-Mg carbonates, in a clean condition, are water wettable... 

Mineralogical analysis of the carbon skeldons of about 50 species from New Zealand showed that they were formed of mixtiues of calcite and aragonite, in which the proportion of caldte ranged from 0% to 100%, with a mean value of 85%. The rate of replacement of calcium by magnesium in calcite varies among species from 0% to 11% (Smith, Nelson, and Spencer, 1998). 

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