The Ring Monstrance from the Loreto treasury in Prague: handheld Raman spectrometer for identification of gemstones (original) (raw)

Raman Spectroscopy of Gemstones on the Necklaces from Ancient Graves at the Castle of Devín

2013

The subjects of Raman and X-ray analyses were the beads from two necklaces found in ancient graves from the 11 and 12 centuries at the Castle of Devín. One of the necklaces (Fig. 1), consisting of 23 beads, was found in tomb 12/1980. Inside the grave, an incomplete skeleton of a woman was found, oriented in the west – east direction. The skull, shoulder blades and lower limbs were preserved in good condition. The grave contained a rich inventory: a silver ear-ring at the left side of the skull, a necklace between the shoulder blades and a ring on the right side at the height of the right hand. The other necklace, consisting of six stones (Fig. 2), was found in grave 145/1985 in which, similarly like in the first grave, a woman’s skeleton was discovered. The stones were found below the mandible. All beads are drilled through axially. Results from systematic excavations performed between 1980 and 1987 were evaluated by Plachá and Divileková [1].

Raman Characterization of Gemstones from the Collection of the Byzantine & Christian Museum

A very significant component of the collect ion of gold jewellery in the By zantine Museum of Athens consists of the Mytilene Treasure fro m the island of Lesbos. Despite the importance of the Mytilene Treasure, one of the most significant hoards of the 7th century A.D. fro m the Aegean area, no previous systematic study has been dedicated to it since its discovery in 1951, except for b rief entries in exh ib ition catalogues [Chalkia, 2008].

Applications of Raman spectroscopy to gemology

Analytical and Bioanalytical Chemistry, 2010

Being nondestructive and requiring short measurement times, a low amount of material, and no sample preparation, Raman spectroscopy is used for routine investigation in the study of gemstone inclusions and treatments and for the characterization of mounted gems. In this work, a review of the use of laboratory Raman and micro-Raman spectrometers and of portable Raman systems in the gemology field is given, focusing on gem identification and on the evaluation of the composition, provenance, and genesis of gems. Many examples are shown of the use of Raman spectroscopy as a tool for the identification of imitations, synthetic gems, and enhancement treatments in natural gemstones. Some recent developments are described, with particular attention being given to the semiprecious stone jade and to two important organic materials used in jewelry, i.e., pearls and corals. Figure Pictures of a pyrope-almandine garnet and of a needle-shaped inclusion. The Raman spectrum of the inclusion is characteristic of rutile

Raman Microspectroscopy of Garnets from SFibulae from the Archaeological Site Lajh (Slovenia)

Minerals

Garnets (19 pieces) of Late Antique Sfibulae from the archaeological site at LajhKranj (Slovenia) were analysed with Raman microspectroscopy to obtain their mineral characteristic, including inclusion assemblage. Most garnets were determined as almandines Type I of pyralspite solid solution series; however, three garnets showed a higher Mg, Mn and Ca contents and were determined as almandines Type II. Most significant Raman bands were determined in the range of 169–173 cm−1 (T(X2+)), 346–352 cm−1 (R(SiO4)), 557–559 cm−1 (ν2), 633–637 cm−1 (ν4), 917–919 cm−1 (ν1), and 1042–1045 cm−1 (ν3). Shifting of certain Raman bands toward higher frequencies was the result of an increase of the Mg content in the garnet composition, which also indicates the presence of pyrope end member in solid garnet solutions. Inclusions of apatite, quartz, mica, magnetite, ilmenite, as well as inclusions with pleochroic or radiation halo and tension fissures (zircon), were found in most of the garnets. Rutile ...

In situ identification of gemstone beads excavated from tombs of the Han Dynasties in Hepu county, Guangxi Province, China using a portable Raman spectrometer

Journal of Raman Spectroscopy, 2014

A portable Raman spectrometer was used for the in situ nondestructive analysis of precious gemstone beads collected in the Han‐Cultural Museum of Hepu county. These beads dated to the Han Dynasties (206 bc to 220 ad) were unearthed from the Hepu county, which was one of the important ancient ports along the Maritime Silk Road, Guangxi Province. Gemstone beads made of beryl group minerals (e.g. aquamarine, goshenite and heliodor) and almandine, which had formerly been mistakenly regarded as coloured quartz beads, were successfully identified. These beryl beads were the earliest known ones ever found in China. In addition, some beads made of amethyst, chalcedony and citrine were also determined. Referred to the research results reported for other artefacts from Hepu county and other places, the possible provenances of these gemstone beads are discussed briefly. The present research provides valuable information for the early trade between south China and South Asia through the Maritim...