Infrared and Raman Spectral Characteristics of High-Quality Green Feicui from Guatemala

Currently, spectroscopic research on high-quality Feicui from Guatemala remains insufficient. In this study, the conventional gemmological methods, infrared spectroscopy, and laser Raman spectroscopy were used to test the 36 high-quality green Feicui samples "Maya green" from Guatemala, to systematically analyze the spectral characteristics and mineral components, and provide critical references for the identification of high-quality Feicui from Guatemala. The infrared and laser Raman spectroscopy results indicate that the characteristic peaks of high-quality green Feicui samples from Guatemala correspond closely with the primary absorption peaks of omphacite. The IR spectra of samples with varying colour grades exhibit slight deviations from standard mineral spectra; however, the overall peak line combinations remain largely consistent. Most samples' Raman spectra match the Raman characteristic peaks of omphacite. A few samples display Raman shift peak combinations typical of omphacite, but with transitional features toward jadeite, potentially due to isomorphic substitutions of Na, Al, Ca, Mg, and Fe. In some samples, the narrow and sharp half-width of the Raman peaks indicate a high degree of crystallization within the Feicui.