GROWTH OF EMERALD CRYSTALS BY THE EVAPORATION OF LI2O-MOO3 FLUX

The growth of emerald (Be3Al2Si6O18:Cr) crystals by an isothermal technique involving the evaporation of Li2O-MoO3 flux is reported. The crystal growth was conducted by heating a mixture of solute and flux at 1100 degrees C for 20-100 h. The evaporation loss of flux depended upon the amount of Li2O added to MoO3 and the holding time. Emerald crystals of length up to 3.4 mm and width 2.4 mm in size were readily obtained. The crystals were transparent and exhibited the typical emerald-green colour. The crystal sizes were dependent on the evaporation loss of flux. The emerald crystals were 12-sided prisms bounded by well developed faces with aspect ratios in the region of 1.2 to 1.9. The density and IR spectra of the crystals were measured. It was found that Li2O-MoO3 was a very suitable flux for growing emerald crystals readily.