Identification of Turquoise and its Imitations with Infrared spectroscopy

Description

Turquoise is a complex basic copper aluminum phosphate best represented by the formula Cu(Al,Fe)6(PO4)4(OH)8.4H2O. The color turquoise has been named after the mineral and is typical for the species, although variations between green and blue can occur. The material has been used in jewelry since ancient times, especially in Persia and by Indian tribes in America. Nowadays it is still popular and besides the purely natural material several imitations or modifications are on the market. Starting from inorganic materials which are simply soaked with color or coated with a varnish, via natural material which has been reinforced or sintered with glass, to fully synthetic products – almost everything is available and has been used. Whereas conventional gemological identification methods are rather limited with non-transparent materials, infrared spectroscopy has proven to be a fast and powerful technique for the identification of turquoise and its imitations (Fig. 1).

Period	21 Sept 2015
Event title	16 th Austrian Chemistry Days
Event type	Conference
Location	AustriaShow on map