Abstract
Synthesrs of single crystals under high pressure and high-temperature conditions was described for geophysically important silicates. Crystal growth is generally enhanced at high temperatures very close to the phase boundary, which is effective to obtain crystals of up to 200 μm in siz for β, γ-Mg_2SiO_4, garnet-, and ilmenite-types of MgSiO_3. In crystal growth of SiO_2 stishovite and perovskite-type of MgSiO_3, however, fluxes such as H_2O and Li_2WO_4 have been found to play important roles. Significance of the large single crystals of high pressure silicates was pointed out from the geophysical point of view.
