Raman Investigations to Identify Corallium rubrum in Iron Age Jewelry and Ornaments

Abstract

During the Central European Iron Age, more specifically between 600 and 100 BC, red precious corals (Corallium rubrum) became very popular in many regions, often associated with the so-called (early) Celts. Red corals are ideally suited to investigate several key questions of Iron Age research, like trade patterns or social and economic structures. While it is fairly easy to distinguish modern C. rubrum from bone, ivory or shells, archaeologists are confronted with ancient, hence altered, artifacts. Due to ageing processes, archaeological corals lose their intensive red color and shiny surface and can easily be confused with these other light colored materials. We propose a non-destructive multi-stage approach to identify archaeological corals amongst other biominerals used as ornament during the central European Iron Age with emphasis on optical examination and mobile Raman spectroscopy. Our investigations suggest that the noticeably high amount of misidentifications or at least uncertain material declarations existing in museums or even in the literature (around 15%) could be overcome by the proposed approach. Furthermore, the range of different materials is higher than previously expected in archaeological research. This finding has implications for contemporary concepts of social structures and distribution networks during the Iron Age.

DNA fingerprinting: an effective tool for taxonomic identification of precious corals in jewelry

“…Two samples (18,46) formed a sister clade to the former group with the posterior probability value 1. Finally, seven identical samples (1,2,25,33,42,44,50) were same as sequences of Pleurocorallium niveum. These were grouped together as an unresolved tree branch.…”

Koráliky z germánskej rezidencie v Cíferi-Páci (juhozápadné Slovensko) / Beads from the Germanic residence at Cífer-Pác (southwest Slovakia)

“…2: 28-29) boli zaujímavé tým, že jeden z nich bol obrusovaný a druhý pravdepodobne odrážal svoj prírodný tvar -tvar koralového konárika. Z pohľadu identifikácie ide o koral červený Corralium rubrum L. (predtým Gorgonia nobilis), ktorý sa vyskytuje v oblasti Stredozemného mora ako je ostrov Sardínia, Korzika, Elba, južná časť Apeninského poloostrova, oblasť východného pobre žia Jadranského mora, ostrovy v Egejskom mori, oblasť Malej Ázie, Baleárske ostrovy, oblasť Baleárskeho mora a oblasť pobrežia severnej Afriky (Tsounis et al 2010) a archeo logické artefakty sa z neho datujú až do obdobia paleolitu (Moradi 2016;Fürst et al 2016).…”

Recognition of big data mixed Raman spectra based on deep learning with smartphone as Raman analyzer

“…The fingerprint characteristic of RS provides a powerful tool for the identification of simple molecules and even complex chemical structures. With the development of laser and optoelectronic technology, portable and handheld RS instrument has been widely used in fields of drug administration, drug trafficking, chemical defense, rail transportation security, airport security, and jewelry identification [5][6][7][8]. Furthermore, surface enhanced Raman Scattering technology has increased the sensitivity of RS by 6-8 orders of magnitude, which makes RS trace detection possible.…”