gems, corundum, Sri Lanka.12, geology

Extensive gem-bearing gravel deposits are found in the coastal area of the lower Walawe Basin, between Ranna and Pallemalala in the Hambantota District (Figure 1). These deposits hold significant geological value for studying paleo-stratigraphy, geoarchaeology, and sea-level changes. The gem fields primarily contain corundum minerals, including ruby, sapphire, and cat’s eye, which are associated with quartz and ironstone gravel. These deposits were formed as fluvial material under arid climatic conditions during the last glacial period. This study aims to examine the geological, archaeological, and economic significance of these gem fields while also assessing the environmental degradation caused by gem mining in the Hambantota District.