Preparation and Basic Properties of Praseodymium-Neodymium-Chromium Containing Imitation Gemstone Glass

Imitation gemstone glass has numerous characteristics, including low cost, rich colour, stable colouring, and the formation of colour-changing effects that can meet the jewellery market demand for beautiful gemstones of middle and low grades. In this study, four types of gem-imitating glass were prepared by the elemental substitution of praseodymium, neodymium and chromium elements based on rare earth glass and examined by combining refractive index, density, spectral characteristics and colour parameters. Sample 1 contained only Pr₆O₁₁ and showed a golden-yellow colour like chrysoberyl. Sample 2 contained only Nd₂O₃ and showed a blue-purple colour like amethyst. Sample 3 contained Pr₆O₁₁ and Nd₂O₃ and appeared green under D65 light source and red under A light source, with a colour-change effect like alexandrite. Sample 4 contained Pr₆O₁₁, Nd₂O₃ and Cr₂O₃ and showed a highly saturated green colour like emerald because of the strong colouring effect of Cr³⁺ in the glass. The findings revealed that all four samples are transparent, with a refractive index greater than 1.5 and a density higher than 2.6 g/cm³. The comprehensive performance of the four imitation gemstone glasses can be found in the corresponding natural gemstones, which has a certain practical value.