Gemstone analysis
Precise analysis of the origin, authenticity and treatment of natural gemstones with LIBS
A major challenge in the field of gemmology is the systematic determination of decisive quality characteristics, including type, origin, authenticity and purity. While in the past, the identification of synthetic gemstones in particular was a demanding task, there is now a need to identify not only the place where they were found, but also the treatments used to artificially enhance the color of natural gemstones.
Diffusion treatment of gemstones
Beryllium diffusion treatment of sapphires is now a very frequently used method to specifically change the color and therefore the value of the gemstone. Dark blue sapphires are predominantly lightened in color. The very rare padparadscha sapphire with its characteristic orange-pink color, derived from the Sinhalese word for lotus flower, is one of the most sought-after specialties. Due to the artificial beryllium diffusion treatment, an originally pink or orange sapphire can take on the typical padparadscha color and is therefore particularly difficult to distinguish from the naturally occurring color variety of this corundum.
Detection of beryllium with LIBS
The metal beryllium is a very light chemical element that cannot be measured with the majority of established analytical methods in gemmology. LTB’s µ-LIBSlab is a reliable LIBS based measurement system for the detection of beryllium diffusion treatment of sapphires. It enables the detection of the characteristic beryllium emission line at 313.1 nm (Be II Doublet) precisely down to the single-digit ppm range. Laser-induced plasma spectroscopy (LIBS) is one of the few quasi-destructive measurement methods with a versatile range of applications in gemmology that enables qualitative and quantitative multi-element analysis, particularly of light elements with single-digit ppm proportions in the gemstone, without sample preparation.
LIBSLAB: modular LIBS measurement system
The metal beryllium is a very light chemical element that cannot be measured with the majority of established analytical methods in gemmology. LTB’s µ-LIBSlab is a reliable LIBS based measurement system for the detection of beryllium diffusion treatment of sapphires. It enables the detection of the characteristic beryllium emission line at 313.1 nm (Be II Doublet) precisely down to the single-digit ppm range. Laser-induced plasma spectroscopy (LIBS) is one of the few quasi-destructive measurement methods with a versatile range of applications in gemmology that enables qualitative and quantitative multi-element analysis, particularly of light elements with single-digit ppm proportions in the gemstone, without sample preparation.
