The application of the Laser Induced Breakdown Spectroscopy (LIBS) to gemmological materials is well known for the gemstone treatment detection but LIBS can also provide a useful contribution in mineralogical studies in which the chemical analyses is essential, playing a key role in the studies on the origin of minerals (Agrosì et al., 2014). The possibility to detect simultaneously all elements, including also light elements such as boron, lithium, and beryllium in a fast way and without sample preparation its clearly a great advantage of the LIBS. Moreover this technique is able to detect chromophorous elements even if they are in very low concentration. Nevertheless the main problems affecting LIBS are the difficulties to perform quantitative analyses and the partial destructivity of the method. Recently, with the development of the technique and in particular with the development of a new softwares there is also the possibilities to perform quantitative analyses with or without calibration. The last examples are the standard Calibration-Free LIBS and the One Point Calibration LIBS, CF-LIBS and OPC-LIBS respectively (Cavalcanti et al., 2013). The improvement of the instrumentation performance and the possibility to focalize the laser beam with an optical lens of a microscope allow to obtain an high resolution and a low destructivity of the sample. Moreover, the use of a double-pulse laser produce a signal enhancement useful for the quantitative chemical analyses guaranteeing a minimal sample damage. In this way we may obtain a considerable improvement on the detection limit of the trace elements, whose determination is essential to define the origin of gemstones. In the mineralogical studies the μ-LIBS appear very attractive because the possibility to select the smallest sampling areas ensures a better reconstruction of the chemical zoning and consequently allows to stimate the rock forming condition because the chemical zoning is sensitive to the changing of the physical and chemical parameters. Some cases of study have been performed on beryls and corundums with different objectives and the results will be discuss.
Application of Laser Induced Breakdown Spectroscopy on gem quality minerals: some cases of study
TEMPESTA, GIOACCHINO;AGROSI', Giovanna;
2014-01-01
Abstract
The application of the Laser Induced Breakdown Spectroscopy (LIBS) to gemmological materials is well known for the gemstone treatment detection but LIBS can also provide a useful contribution in mineralogical studies in which the chemical analyses is essential, playing a key role in the studies on the origin of minerals (Agrosì et al., 2014). The possibility to detect simultaneously all elements, including also light elements such as boron, lithium, and beryllium in a fast way and without sample preparation its clearly a great advantage of the LIBS. Moreover this technique is able to detect chromophorous elements even if they are in very low concentration. Nevertheless the main problems affecting LIBS are the difficulties to perform quantitative analyses and the partial destructivity of the method. Recently, with the development of the technique and in particular with the development of a new softwares there is also the possibilities to perform quantitative analyses with or without calibration. The last examples are the standard Calibration-Free LIBS and the One Point Calibration LIBS, CF-LIBS and OPC-LIBS respectively (Cavalcanti et al., 2013). The improvement of the instrumentation performance and the possibility to focalize the laser beam with an optical lens of a microscope allow to obtain an high resolution and a low destructivity of the sample. Moreover, the use of a double-pulse laser produce a signal enhancement useful for the quantitative chemical analyses guaranteeing a minimal sample damage. In this way we may obtain a considerable improvement on the detection limit of the trace elements, whose determination is essential to define the origin of gemstones. In the mineralogical studies the μ-LIBS appear very attractive because the possibility to select the smallest sampling areas ensures a better reconstruction of the chemical zoning and consequently allows to stimate the rock forming condition because the chemical zoning is sensitive to the changing of the physical and chemical parameters. Some cases of study have been performed on beryls and corundums with different objectives and the results will be discuss.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
