Published Paper Details:

The occurrence of gemminerals is a rare phenomenon and in the same way the geological information, geophysical and geochemical information are also very rare. Visakhapatnam District of Andhra Pradesh state in India, located in parts of Eastern Ghats comprising valuable mineral resources especially gemminerals. The precious and semi-precious stones of Alexandrite, Chrysoberyl, Chrysoberylcat's eye, Garnets, Tourmaline, Sillimanite and a variety of quartz group are known to occur in this region. The gemstones are very much engulfed within the pegmatite both in primary and secondary stages. The geological studies on exploration, mining and environmental planning have shown very promising results, where the gem mineral resources were estimated to a depth of 15 mts. from the surface. Geoelectrical resistivity surveys have been utilized and the results are favorable and correlated with the surface geological features. The geo-chemical investigation carried out for the hostrocks and the associated gem-variety stones and analyzed for their major and minor elemental concentrations. Geochemical analysis of the petrological members of gem bearing tracts of the region was carried out by ICP-MS and elemental concentrations were determined. A few of the samples were processed for XRD analysis. The following important points are noted in (i) Invaluable gem minerals are found in association with the Khondalite suite of rocks, as per their geochemical evaluation. (ii) The secondary pegmatitic body indicated all the mineralogical characteristics of the primary pegmaties in a deeply altered stage (iii) The colluvium forms as the target of explanation for the gem minerals in this region. (iv) The study shows that the element fluorine is endangerous to the local rural people, which may result fluorosis in parts of the this region.