Analysis of the chromite inclusions found in nephrite minerals obtained from different deposits using SEM-EDS and LRS

• Published in: Journal of Raman spectroscopy 2011-09, Vol.42 (9), p.1808-1811
• Main Authors: Zhang, Z. W., Gan, F. X.
• Format: Article
• Language: English
• Subjects: Aluminum; Chromite; Deposition; Inclusions; Laser Raman spectroscopy; Minerals; nephrite; peak position; Raman spectroscopy; SEM-EDS; Spectrometers; Wavenumber
• ISSN: 0377-0486; 1097-4555; 1097-4555
• DOI: 10.1002/jrs.2963

Scanning electron microscopy with energy dispersive spectrometer (SEM‐EDS) and laser Raman spectroscopy (LRS) were used to analyse the chromite inclusions found in four samples of the mineral nephrite that were obtained from Taiwan (one), Manasi in China (two) and New Zealand (one). The chromite inclusions found in sample HL‐1 (Taiwan) contain low contents of Mg and Al, as well as a characteristically high Zn content. The most significant finding, however, was that HL‐1 could also be distinguished from the other samples by the lower wavenumbers of the positions of the peaks that belong to the A1g, F2g(1) and Eg modes. Compared to the difference in compositions, the difference in the positions of the peaks in the Raman spectra of the chromite inclusions, as revealed by LRS, can more easily be used to distinguish between samples of nephrite that have been obtained from different deposits, and in particular to identify the provenance of the raw material used in ancient nephrite artefacts, in view of the fact that LRS is non‐destructive and easy to apply. Copyright © 2011 John Wiley & Sons, Ltd. Archaeological studies benefit from the use of a range different techniques, especially those that are non‐destructive. We here report on a first tentative approach to analyse the chromite inclusions found in samples of nephrite obtained from different deposits using scanning electron microscopy with energy dispersive spectrometer (SEM‐EDS) and laser Raman spectroscopy (LRS). We discuss the shifts in wavenumbers of the peaks as revealed by LRS, as well as the difference in the chemical compositions as obtained using SEM‐EDS.