Raman and FTIR spectra of nephrites from the Złoty Stok and Jordanów Śląski (the Sudetes and Fore-Sudetic Block, SW Poland)

Abstract <p>Raman and infrared spectroscopy are fast, simple and useful methods of identifying and distinguishing between different rock samples, which often originate from different sources. We analyzed nephrite samples from Polish deposits (Złoty Stok in the Sudetes and Jordanów Śląski in the Fore-Sudetic Block). Studied nephrites amphiboles, with the general formula (Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂), magnesium and iron contents, in terms of Fe/(Fe+Mg) per formula unit, are as follows: Jordanów Śląski (0.06–0.10), Złoty Stok type 1 (0.10–0.20) and Złoty Stok type 2 (0.04–0.18). Our spectroscopic study is consistent with results of previous petrographic microscopy, scanning electron microscopy and chemical composition of constituting minerals, measured by the electron microprobe; which methods were applied to the same nephrite deposits. Results of Jordanów and Złoty Stok nephrites studies were compared with data available in literature, which confirmed petrographic composition of studied samples. In addition, in case of actinolite nephrite samples (Fe/(Fe+Mg) &gt; 0.10), qualification of the studied minerals to actinolite with content of Fe ion below 15% and 30% in sample from Jordanów Śląski and Złoty Stok, respectively, is possible based solely on applied spectroscopic methods. Spectroscopic studies also allowed to note the relationship between the obtained results and the genetic origin (serpentinite-related or dolomite-related) of the studied nephrites.</p> <p>Findings confirmed that spectroscopic methods are not only applicable and useful, but, which is very important in gemological and archaeometric practice, also non-destructive</p>