Chemical–physical characterisation of Early Iron Age glass beads from Central Europe

Natron glass beads reveal proto-Silk Road between the Mediterranean and China in the 1st millennium BCE

“…This 'classic' type of natron glass has been discovered from the 1st millennium BCE context across the Mediterranean area, including Italy [25][26][27][28][29][30] , Greece [31][32][33][34] , and Spain 35 , as well as in the Black Sea region with artifacts from Bulgaria 36,37 and Georgia 38,39 (a summary is given in the Supplementary Information (SI)). Moreover, natron glass was found outside the Mediterranean coastal area, such as Germany 40,41 , Poland 41,42 , and as far as Mali 43 . Intensified glass production in the late Hellenistic period 19,44 eventually set the stage for Roman glass, when natron glass thrived as a focal center of material culture.…”

“…Some of the beads have compositional data reported. The Altdorf beads 41 (EB-b) are made of natron glass, and the beads from Zenghouyi 57 (EB-a, -b, -c), Xujialing 56 (EB-c), Hougudui 15 (EB-c) and Shanghai Glass Museum 64 (EB-a, -b, -d) are likely natron-based as well. Also, Pichvnari beads that may be of EB-b and EB-d types from textual descriptions were reported as natron glass 38 .…”

“…Coloration of the base glasses attests to a shared technological background. Among these eye beads, glass of the same color contains the same colorants and opacifiers: white glass is rich in Sb and Ca, indicating the presence of calcium antimonate 35,36,41,42,56,57,64 ; blue or greenish-blue glass is colored by Cu 36,56,57,64 ; Sb and Pb are high in yellow glass that is colored by lead antimonate 36,41,42,57 ; deep blue glass is colored by Co and mostly also contains some Cu 35,36,41,42,56,57,64 , similar to the Wupu bead. www.nature.com/scientificreports/ Similarity in typology and composition strongly suggests a common origin.…”

“…Likely composition for a type is inferred from samples of that type with trace element information reported. Sites of discovery: EB-a: Dren-Delyan (Bulgaria) 36 , Pichvnari (Georgia) 39 , the tomb of Zhaoqing (north China) 64 , Zenghouyi (central China) 57 , and Shanghai Glass Museum (unspecified context) 64 ; EB-b: Altdorf (Germany) 41 , Owidz (Poland) 42 , Dren-Delyan 36 , Pichvnari 39 , National Museum of Georgia (unspecified context, personal visit), Zenghouyi 57 , and Shanghai Glass Museum 64 ; EB-c: Xujialing (central China) 56 , Zenghouyi 57 , Hougudui (central China) 15 , and Pichvnari 39 ; EB-d: from Son Mas (Spain) as fragments 35 , and from Svaneti Museum in Georgia (unspecified context, personal visit), National Museum of Georgia, and Shanghai Glass Museum 64 . Additionally, eye beads that might be of EB-a, EB-c, and EB-d types were reported from Filippovka I burials in Southern Urals that were considered to date to 4-3 C. BCE (images inconclusive 65,66 www.nature.com/scientificreports/ Proto-Silk Road.…”

Early Iron Age ‘black’ glass in Southwestern Iberia: typology, distribution, and context

“…While the number of analyzed samples is very reduced and, therefore, of very limited statistical (Reade et al, 2009;Purowski et al, 2012Purowski et al, , 2020Conte et al, 2016;2018;Agua et al, 2017;Van Ham-Meert et al, 2019) still yields some suggestive results. First of all, a comparison of the content in magnesia and potash (Fig.…”