Internal Features of Glass Filled Ruby Samples Probed by EPMA

Abstract

Glass filled ruby is one of the treated rubies that consist of the additive substance to improve the clarity of ruby. There are many variations of glass filled rubies based on their chemical additives to fulfill the fractures during heat treatment process. However, the quality and the price of ruby are related to the different types of glass materials. Thus, the aim of this study is important to classify the type of glass materials inside the ruby samples by a non-destructive property such as their internal features. In this research, the glass filled ruby samples were collected including lead-glass filled rubies and high alumina-glass filled rubies. The surface and internal features in macro scale of the samples were observed by gem microscope. Moreover, their internal features were magnified to detect the chemical content of fractures and groundmass using electron probe micro analyzer (EPMA). As the results, there are high PbO and SiO2 in the fractures of lead-glass filled rubies. Besides, there are high Al2O3 mixing with SiO2 in the fractures of high alumina-glass filled rubies. It could be summarized that the varieties of glass filled ruby samples have been classified by the glass materials in their fractures.