Elemental characterization of Nigerian Tourmaline, Fluorite and Topaz by instrumental neutron activation analysis

Instrumental Neutron Activation Analysis (INAA) was employed in determination of the major and trace element constituent in tourmaline, fluorite and topaz collected from the gemstone mineralization within the SW-NE trending pegmatite zone, central Nigeria. Also, the trace contaminants in these gemstones were determined. The major elements constituent in tourmaline were Al (119,800 ppm), Mn (4,348 ppm), Na (15,540 ppm) and Fe (34,290 ppm); fluorite Ca (552,000 ppm) and topaz Al (322,800 ppm) while the trace contaminants were in the range of Sc (6.6 ppm) to La (68 ppm; Hf(1.00 ppm) to Zn (112 ppm) and Ta (0.9 ppm) to La (95 ppm) respectively in these gemstones. No attempt was made to identify the molecular structure of the gemstones as oxygen, fluorine and silicon contents in any of them were not determined. The health implications of the trace contaminants in the gemstones are highlighted.