I vetri di Frattesina. Caratterizzazione crono-tipologica, archeometria e confronti nell’ambito della tarda età del Bronzo dell’Europa centro-orientale e del Mediterraneo. In “Frattesina cinquant’anni dopo. Il Delta del Po tra Europa e Mediterraneo nei secoli attorno al 1000 a.C.”.

This work concerns the typological and archaeometric topics of the mixed alkali (LMHK Low Magnaiium High Potassium) glass finished products from the protohistoric settlement of Frattesina di Fratta Polesine (Veneto region - north eastern Italy) and its necropolises (Narde I and II and Fondo Zanotto). For what concerns the typological analysis, a previous preliminary work (BELLINTANI, STEFAN 2009) is here updated with data from the excavations carried out in the settlement (1974-1989) by Anna Maria Bietti Sestieri, from the II nucleus of the Narde necropolis and from new surface research (years 2014-2016). These data were also discussed in the light of the most recent studies on glassy materials from the Late Bronze Age Europe and Eastern Mediterranean. Currently the number of glass products, mostly coming from the settlement area, amounts to 3,039 artifacts, of which 3,035 ornamental elements (3,033 beads, 2 anthropomorphic pendants) a small container (alabaston) and some vascular fragments in ceramic decorated with glass on the surface. The most represented category, i.e. beads, is made up, mostly, by the group of monochrome beads and specifically of the ‘annular bead’ type (2,837; i.e. 95.58% of all the beads found). Typologically more diagnostic, but definitely lower in number (199; 4.52%) are the larger beads, of which 137 are decorated with glass of a that of the body. As regards the chronology of this artisan activity in rattesina, the initial moment remains not well defined, perhaps datable to a more or less advanced moment of the initial final Bronze Age (FBA1) or of the transition to the central one (FBA2). The moment of maximum development corresponds to FBA2, a period in which all the main types of beads are present. With the start of the FBA3, processing seems to undergo a drastic decline. On the other hand, no artifacts refer to the Early Iron Age (EIA1), the last moment in the life of the protohistoric community. An overview of the main elements of comparison among the 137 beads decorated with glass of a different colour from that of the body, referable to the two large groups of beads with wire decoration (spiral or wavy) or with drops (‘eye’ decoration), is here presented. In particular, we focus on the origin of the types, almost always derived from the eastern Mediterranean and with precedents in the group of the ‘brown glasses’ (HMBG: High Magnesium Brown Glass), probably of North Italian production. The distribution of beads, which by type and composition recall those produced in Frattesina, extends over a very vast area, from the Mediterranean Levant and the Aegean to the North Sea, and concentrates in the regions immediately south and north of the Alpine Arc, along strategic communication routes such as the Adige and Rhein Valleys, probably related to the movement of other commodities and prestige goods (Baltic amber, copper from the Alps, perhaps tin). Based on all the available literature archaeometric data, the main chemical and mineralogical characteristics of the glass from Frattesina and its necropolis, Fondo Zanotto and Narde, are reviewed. A short description of the glass compositions, together with the type of raw materials and coloring techniques used are presented. In specific the Frattesina glass are made with sand and a fluxing agent that is of two different types: 1) potash plant ash; and 2) mixed alkali flux, possibly derived from mixed alkali plant ash or a mix of K-rich and Na-rich plant ashes. Blue is the more diffuse color, the wide range of shades are related to the type and quantity of chromophores present in the glass (Cu, Co and Fe). Moreover, whitish-pale green, red, white and green glasses are present. All these different colors are obtained with the use of one or even two (for red and white glasses) specific coloring techniques. In addition, we present a new report of beads, mainly annular, in mixed alkali glass from funerary contexts of the Belozerka culture, widespread in the region north of the Black Sea (Ukraine, Moldova) and dating back to the passage from the Bronze to the Iron Age. The presence in Belozerka grave goods of glass beads of a composition similar to that of LMHK glasses from Western Europe, along with raised violin bow fibulae of Italian and/or Aegean type, suggests a possible transmission of artifacts, fashions and technologies along paths that were to connect northern Italy and the central-eastern Alps to Eastern Europe, through the Danubian-Carpathian region. Such an hypothesis could also be supported by the exceptional context of Hordeevka, also in Ukraine, where numerous amber beads of the Tiryns and Allumiere types of probable Italian production are attested. The composition of the glasses from the Belozerka culture has been compared with the chemistry (and mineralogy) of the glass from Frattesina. Interestingly, the ‘recipes’ for the glass productions seem to be very similar: sand and K-rich ashes or mixed alkali flux are use also for the Belozerka glass. On the other side, variations in both major and minor elements contents suggest the use of different raw materials. In addition, the coloring techniques used in the two areas show peculiar aspects. All these observations suggest that the glass from Frattesina and from the Belozerka culture are originated from different production centers.