Gemological and Chemical Characterization of Varicolored Gem-Grade Spinel from Mogok, Myanmar

Spinel is a precious gem with long history, but people are far less familiar it. Previous studies on Mogok spinel from Myanmar focused inclusion analysis, chromogenic mechanism single-color gemstone and heat treatment, whereas systematic varicolored gem-grade lacking. In this study, the gemological geochemical analysis of four colors samples were carried out for basic gemology, morphology identification, spectroscopy geochemistry. The aim was to explore occupation elements spinels in crystal structure, as well geological geodynamic conditions formation. characterized by octahedral negative crystals filled calcite chondrodite inclusions, indicating that they derived marble metamorphic-type deposit. magnesia–alumina (MgAl2O4). contents V Cr generally high, significant high content Zn being most characteristic, trace vary greatly. infrared spectra different basically similar. According UV–Vis spectrum, pink red mainly colored and/or V, orange V. Two wide absorption bands range 300~600 nm attributed spin-allowed transition spin-forbidden Cr3+ V3+. purple Fe spectrum TFe2+. This study favorable supplement research various multiple perspectives.