Characterization of Limestone Sample from Northeast India and its Implication on Beneficiation

Two limestone samples, from the same source (Assam, north-east India) have been petromineralogically characterized. In hand specimens, both samples are quite similar and are highly fossiliferous. Under optical microscope the fossils that are indentified belong mostly to two different Phy-llum, viz., Protozoa and Mollusca. The Protozoans are mainly Foraminifera and the Molluscans are Lamellibran-chia. Both categories have been petrified to calcium carbonate only and the fossils are embedded in a lime matrix. Due to the dominance of Nummulite fossils, the samples can be named as 'Nummulitic limestones'.The fossil records indicate that the limestones may be of Eocene age (< 65 million years).