Origin of Blue-Water Jadeite Jades from Myanmar and Guatemala: Differentiation by Non-Destructive Spectroscopic Techniques

Abstract

Listen

Translate article

Identifying the origin of jadeite jades has become increasingly important from both mineral resource and metamorphic geology perspectives. In this study, we differentiate Myanmar gem-quality blue-water jadeite jades from their Guatemala counterparts via integrating various non-destructive spectrographic techniques, including X-ray fluorescence (XRF), Ultraviolet-Visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. Our results show that the Myanmar blue-water jadeite jades are structurally homogenous with very few impurities, while their Guatemala counterparts commonly have a yellowish margin with scattered white albite and disseminated greenish inclusions of omphacite and (minor) aegirine-augite. Geochemically, the UV absorption spectral data indicate that the Guatemala samples have higher total Fe and Fe2+ contents, but lower Fe3+ content than the Myanmar samples. The Guatemala samples also have higher omphacite content (lower molar Na/(Na+Ca) ratio, as reflected by the lower IR absorption peak wavenumber) and higher heterogeneity (as reflected by the ~680 cm−1 Raman peak shift difference) than that from Myanmar. Major differences are also discovered in the blue series (Myanmar: 0–0.7 cm−1; Guatemala: 1.7–3.2 cm−1) and blue-green series (Myanmar: 6.9 cm−1; Guatemala 13.7 cm−1) of the Raman peak shift difference, which altogether can provide a novel, nondestructive method for distinguishing blue-water jadeite jades from different origins.