Hydrogeological conditions for the occurrence of two magnesium-rich natural mineral waters in Serbia and their physiological significance

Abstract

Numerous medical studies have shown that magnesium has a remarkable significance for the human physiology. Thus, the possibility of using two magnesium-rich natural waters from Serbia as magnesium supplements and the hydrogeological features of these occurrences are presented through the results of SEM–EDS and XPRD analyses of water dry residues and comparisons with crystalline phases of two types of synthetic magnesium supplements available in the Serbian market. The results indicate that major phases in the dry residues of the water samples are Mg phases, whereas the synthetic supplements (besides Mg phases) contain significant amounts of fillers, such as citric acid and sodium bicarbonate. The mineral phases of dry residues of these two natural mineral waters also indirectly indicate the local hydrogeological conditions during the movement of groundwater. Hydromagnesite, as the main and only crystalline phase in the dry residue of the first Mg-rich (330 mg/l) natural mineral water, indicates a deep groundwater circulation and long-term dissolution of olivine or serpentine minerals, considering that it is tapped from the well in which only gneiss was identified. Smaller quantities of hydromagnesite and higher content of amorphous phase in the dry residue of the second Mg-rich mineral water could probably indicate a rapid circulation and shorter dissolution of serpentine minerals through which the water passes directly near the surface. The high content of Mg-rich crystal phases (up to 80%) in the dry residue of tested waters indicates their high physiological value as (natural) dietary supplements.