[Source Constraints on Turquoise of the Erlitou Site by Infrared Spectra].

Shiyan district in Hubei province is a famous locality of high-quality turquoise with brightcolor, finegrain in the world. Erlitou archacologicalsite, which is about 300km north to the Shiyan Turquoise mine, has been excavated a remarkable number of turquoise artifacts since 2002. Some researchers infer that there was "a road of turquoise" between the two sites in history. In order to check the inference, and identify local features of the turquoises found in Shiyan, and Eelitou site as well, spectra of three turquoise groups from Shiyan, Hubei and one group of Erlitou unearthed samples were obtained by means of IR. Their spectra have visible differences in the 1 200-950 and 700-400 cm(-1) range. Peak 1 174 cm(-1) appears only in samples from Wenfeng, and from 700 to 400 cm(-1), 5 peaks show in samples from Wenfeng while 7 peaks emerge from the other two sites. Turquoises in Erlitou site have similar spectra to those from Qingu and Yungaisi, and are more similar to Yungaisi of peak around 1 159 cm(-1). According to A = lg(1/T) , intensity of transmittance spectra were calculated and then Ratios(A783 cm(-1)/A837 cm(-1)) were yielded. The ratios of samples from Qingu, Wenfeng, Yungaisi and Erlitou site are 0.819-0.920, 0.870-1.010, 0.806-0.860 and 0.827-0.878 respectively, allowing for a suggestion that turquoise in Erlitou site was the most probable from Yungaisi. This research can be used as example for identifying origin of the unearthed turquoise relics, which is more likely a good tool for archeological research.