Geological history and the importance of pegmatite veins.
Pegmatite veins are common in almost all the rock type in Ranchi city of India. by Dr. Nitish Priyadarshi Pegmatite, meaning “joined together,” was first applied to graphic granite sometime before 1822. Subsequently, it has been extended to refer to any abnormally coarse grained rock of overall igneous character. The term “pegmatite” was first used by a French mineralogist René Haüy but he used this term as a synonym of graphic granite. Contemporary meaning was given to the rock type in 1845 by an Austrian mineralogist Wilhelm Heidinger. Most of pegmatites are more than 1 centimeter across; grains up to a meter or two across are relatively common; and individual crystals up to several meters in greatest dimension have been reported. In any case, no matter how large the grains, most pegmatites have typical igneous rock textures. Pegmatites are associated with plutonic or intrusive rocks and were evidently formed by slow crystallization at considerable depths below the surface. Individ...