The term hydrothermal is purely of geological origin. It was first used by the
British geologist, Sir Roderick Murchison (1792 2 1871), to describe the action of
water at elevated temperature and pressure in bringing about changes in the Earth’s
crust, and leading to the formation of various rocks and minerals. Geologists carried
out the earliest work on the hydrothermal technique in the nineteenth century
in order to understand the genesis of rocks and minerals by simulating the natural
conditions existing under the Earth’s crust. However, materials scientists popularized
the technique, particularly during 1940s. Schafhautl, who obtained quartz crystals
upon freshly precipitated silicic acid in a Papin’s Digester, carried out the first
hydrothermal synthesis in 1845. Subsequently, hydrothermal synthesis of a wide
variety of minerals was carried out, especially in Europe.