GLASS

Glass is a versatile material as it can be made almost any colour and can be moulded or faceted to give the required appear­ance. However, there are noticeable differences between glass and gems. Glass is generally not as hard as the gemstone that it imitates, and will be able to scratch more easily. Further, its facet edges may appear scratched and worn. There may also be bub­bles or distinctive swirls within the glass, which can be easily seen with the use of a hand lens. A gemologist will also be able to distinguish glass by its single refraction and the value of its refractive index (1.5-1.7), as there are no singly refractive gems with the same refractive index.