Mid-infrared(mid-IR)spectroscopy of 15 demantoid samples from Bagh-eBorj,Esfandagheh district,Kerman Province,Iran,has been studied and their mid-IR and Ultraviolet-Visible(UV-Vis)were compared.The samples has been collected from serpentinites of Esfandahge's Chromium Bearing Ophiolititic complex in Sanandaj-Sirjan Structural Zone,southern Iran.UV-Vis spectroscopy is a suitable method for detection of transition ions responsible for mineral's colour such as demantoid.The UV-Vis spectra of demantoid samples with a colour range of yellowish green to green were slightly different,representing peaks at 392,437,573 and 865 nm related to and 437 and 481 nm bands attributed to.Also the 855 nm band's absorbance changed moderately by the tolerance of Cr content which correlated the green colour.Mid-IR spectroscopy identifies the hydroxyl group.Mid-IR spectra of all samples presented close results in the 3 800-3 400 cm^(-1) region but differences could be observed in the 1 500-800 cm^(-1) area.The two absorption peaks at 3 550 cm^(-1) and 3 596 cm^(-1) are related to hydroxide,which can be present in andradite as a minor component,in the form of structurally bonded OH-.It is needed to be mentioned that from 15 studied sample,6 samples contained"horsetail"inclusions,which confirms their serpentinite geologic origin.
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