In the central part of Indo-Gangetic alluvium in the Unnao district, Uttar Pradesh, India there are many pockets where groundwater shows high fluoride content. Drinking of fluorinated ground water has effected a large population and in many villages more than 80% of the population is suffering from fluorosis. The source of fluoride in groundwater is being geogenic in nature and this research thesis emphasizes on the source mineral releasing fluoride in the groundwater.