A new technique for the analysis of corundum that has undergone heat treatment and beryllium diffusion to resemble one of the most valuable colored stones: vivid orange-yellow gems known as padparadscha is developed in this study. The technique is based on laser-induced breakdown spectroscopy (LIBS), and chemical analysis with inductively coupled plasma-mass spectrometry (ICP-MS) is used to verify the LIBS data. The method can be used to distinguish natural and treated gems, especially in the case of unknown treatments. This study shows that the method can be used to determine the authenticity of gems.
The document details a new technique for analyzing corundum (rubies and sapphires) that have undergone a specific heat treatment process involving the addition of beryllium. This treatment makes it difficult to distinguish treated stones from natural ones using conventional methods.
Researchers utilized Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), specifically coupling a Merchantek UP-213 laser system with an Agilent 7500a ICP-MS, to investigate the distribution of beryllium across gem surfaces. The study successfully identified trace levels of beryllium in treated samples where conventional instrumentation failed.
The study used a Merchantek UP-213 LA system coupled to an Agilent 7500a ICP-MS.
The process involves adding beryllium during heating, which diffuses into the stone and enhances its color, making it difficult to identify as treated.