The use of gems for manufacturing jewels and adorn precious objects, such as royal insignia or liturgical objects, represents a well know routine since ancient times. Considering the value of these objects and the fact that they are often preserved in Museum, the use of a non-destructive and non-invasive analyses techniques for their characterization is required. The study of gems, and in particular the possibility to obtain a certification of nature and provenance of them, represents a relevant procedure for archaeometric issues. In this framework, Raman spectroscopy represents a useful tool being a quick, completely non-invasive and contactless technique which does not require any sample preparation. Moreover, by using Raman spectroscopy it is possible to obtain a large amount of information on gems, namely composition, inclusions and treatments. Among the major commercial gems, ruby is considered one of the most precious gemstones, together with sapphire, emerald and diamond. Ruby is the red transparent gem variety of corundum; the colors are intense red to pink due to traces of chromium3+ ions. In this context, this work is focused on the spectroscopic characterization of different kinds of rubies, by using micro-Raman instrumentations equipped with different laser excitation sources in order to furnish gemological certification and to acquire information about the provenance of the gems. In detail, Raman spectra have been collected on seventeen samples of red loose gems by means a confocal JobinYvon Horiba Labram, equipped with the 473.1 nm excitation lines and a micro-Raman Jasco NRS-3100 apparatus, equipped with laser excitation source at 785 nm. The obtained results allow not only to discriminate rubies from simulant and fakes but also achieve useful information on inclusions and treatments. Therefore, the main aim of this work is test the potentiality of micro-Raman spectroscopy in rubies identification, establishing the basis for the characterization of rubies with portable Raman spectrometers directly in museums on gems mounted in precious and unmovable artworks. In this prospective, this is a work in progress and portable Raman measurements in Sicilian Museum are scheduled with the aim at studying interesting jeweler ancient collections.
Application of micro-Raman Spectroscopy for the characterization of rubies
RANERI, SIMONA
2014-01-01
Abstract
The use of gems for manufacturing jewels and adorn precious objects, such as royal insignia or liturgical objects, represents a well know routine since ancient times. Considering the value of these objects and the fact that they are often preserved in Museum, the use of a non-destructive and non-invasive analyses techniques for their characterization is required. The study of gems, and in particular the possibility to obtain a certification of nature and provenance of them, represents a relevant procedure for archaeometric issues. In this framework, Raman spectroscopy represents a useful tool being a quick, completely non-invasive and contactless technique which does not require any sample preparation. Moreover, by using Raman spectroscopy it is possible to obtain a large amount of information on gems, namely composition, inclusions and treatments. Among the major commercial gems, ruby is considered one of the most precious gemstones, together with sapphire, emerald and diamond. Ruby is the red transparent gem variety of corundum; the colors are intense red to pink due to traces of chromium3+ ions. In this context, this work is focused on the spectroscopic characterization of different kinds of rubies, by using micro-Raman instrumentations equipped with different laser excitation sources in order to furnish gemological certification and to acquire information about the provenance of the gems. In detail, Raman spectra have been collected on seventeen samples of red loose gems by means a confocal JobinYvon Horiba Labram, equipped with the 473.1 nm excitation lines and a micro-Raman Jasco NRS-3100 apparatus, equipped with laser excitation source at 785 nm. The obtained results allow not only to discriminate rubies from simulant and fakes but also achieve useful information on inclusions and treatments. Therefore, the main aim of this work is test the potentiality of micro-Raman spectroscopy in rubies identification, establishing the basis for the characterization of rubies with portable Raman spectrometers directly in museums on gems mounted in precious and unmovable artworks. In this prospective, this is a work in progress and portable Raman measurements in Sicilian Museum are scheduled with the aim at studying interesting jeweler ancient collections.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
