Gem quality minerals are primarily dependent on the presence (or lack thereof) of trace elements and inclusions. In addition, such information also enables an understanding of the origins of these minerals and the environment in which they occurred. Such information is important to understand the genesis of the deposit as well as the quality of the gem mineral. Specifically, in the case of sapphires, a type of corundum (Al2O3), the presence of trace levels of Fe, Ti, and Cr will determine the color and its intensity. Identification of inclusions in the sapphires and mineral associations in lithological units will yield information on the geological process and the associated pressure – temperature (P-T) constraints.
A combination of micro-XRF, SEM-EDS and SEM-CL will expand your workflow analytical capabilities. Micro-XRF is ideal to analyze large areas at the micrometer scale and is a powerful tool for identifying both trace elements or minerals. In contrast, SEM analysis allows a higher spatial resolution required to understand the elemental and mineralogical processes at a high resolution. The benefits and capabilities of each will be discussed to ultimately provide the best workflow for your analytical needs.
Dr. Andrew Menzies
Senior Application Scientist Geology and Mining, Bruker Nano Analytics
Gustavo Miranda-Díaz (Dipl. Geol)
Institut für Mineralogie, Technische Universität Bergakademie Freiberg, Germany