Development of artificial ambliconite gemstones from glass material.

Abstract

The aims of this research to develop glass-based ambliconite gems. Glass was prepared from the formula (40-x)SiO2: 20B2O3: 25Na2O: 15CaO: xHo2O3 mol% where x is the concentration of Ho2O3 (0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol%) have been synthesized by conventional melt quenching technique at 1,200 C for 3 hours. Studied the physical properties and the optical properties of glass The results showed that density, molar volume and refractive index tends to increase according to the increasing concentration of Ho2O3 . The absorption spectra of glass in the wavelength range of 200 to 2500 nm showed nine absorption broadbands at 355, 415, 451, 486, 536, 641, 898, 1150 and 1946 nm, caused by the energy level change in the ground state (5 I8 ) to the excitation state 5G3, (5G,3G)5, 5G6, 5F3, 5F4, 5F5, 5I5, 5I6 and 5I7 respectively. Color analysis in the CIE L*a*b* system showed that the illuminance (L*) was independent of the amount of Ho2O3 concentration added, with the a* value ranging from -0.1455 to - 3.5214, and b* value ranging from 1.3944 to 32.0402. It was found that glass doped with Ho2O3 at 0.5 mol% had L* value of 89.2480, a* value of -3.5670, and b* value of 16.4869. The color value was close to that of real ambliconite in nature and have similar physical characteristics.