Iron Age glass-working in Moravia, Central Europe: new archaeometric research on raw glass and waste — 3rd–first century BC

Known Glass Compositions in Iron Age Europe—Current Synthesis and Emerging Questions

“…Similar conclusions were also reached by comparing trace element patterns and isotopic data of core-formed vessels with Roman "Levantine" glass [42,56,91]. When a large dataset was considered, Mediterranean core-formed vessels showed a link between their chrono-typology and possible sand provenance (Figure 5b): the earliest core-formed vessels belonging to the Mediterranean Group I had high Sr and low Zr content [42,56,91,92], typical of glass made with Levantine or Mesopotamian sand [7,29,[40][41][42][58][59][60][61][62]. Mediterranean II vessels were split into low-and high-Zr clusters, suggesting that Egypt started supplying raw glass to Hellenistic workshops during the 4th century BCE alongside Levant.…”

“…For natron-fluxed glass, low (<200 ppm) and high (300-600 ppm) Sr contents in the final glass are often used as indicators of geological limestone or beach shell fragments used as glass stabilisers, respectively [12]. Many researchers have used Sr concentrations to hypothesise the nature of glass stabilisers used in the Early Iron Age [38,40,56] and in Hellenistic [42,56,57] and Celtic glass [7,58,59]. In particular, the relationship between Sr and Zr has proven to be indicative of the use of shell-rich coastal sands as opposed to zircon-rich inland sands/silica sources for glasses from the Bronze Age to the Roman period, and is often used as a discriminating factor between glass produced in the Levant (possibly with Belus river sands) and Egypt [7,29,[40][41][42][58][59][60][61][62].…”

“…Many researchers have used Sr concentrations to hypothesise the nature of glass stabilisers used in the Early Iron Age [38,40,56] and in Hellenistic [42,56,57] and Celtic glass [7,58,59]. In particular, the relationship between Sr and Zr has proven to be indicative of the use of shell-rich coastal sands as opposed to zircon-rich inland sands/silica sources for glasses from the Bronze Age to the Roman period, and is often used as a discriminating factor between glass produced in the Levant (possibly with Belus river sands) and Egypt [7,29,[40][41][42][58][59][60][61][62]. Some other elements, such as Al and Fe, can also act as stabilisers, and are, in fact, responsible for the preservation of some early natron glasses found in Europe that contain amounts of Ca insufficient to stabilise glass [35,37,38,49].…”

“…belonging to the Mediterranean Group I had high Sr and low Zr content [42,56,91,92], typical of glass made with Levantine or Mesopotamian sand [7,29,[40][41][42][58][59][60][61][62]. Mediterranean II vessels were split into low-and high-Zr clusters, suggesting that Egypt started supplying raw glass to Hellenistic workshops during the 4th century BCE alongside Levant.…”

“…Evidence of ancient primary glassmaking sites is extremely rare [82,104] and no sites dating to the Iron Age are known, making archaeometric analyses essential in understanding the provenance of Iron Age glass. To this end, trace element (e.g., Zr, Sr, Mn, Ti) concentrations are most often used to discern between Egyptian and Levantine sands as sources of silica for glasses made in the Eastern Mediterranean, and by extension, in primary glass production centres [7,20,37,38,[40][41][42][43]59,83,91,92]. As stated previously, the initial period of Early Iron Age is characterised by parallel production of natron-fluxed glass (LMG) from the Eastern Mediterranean, as well as several unique glassmaking types (Figure 1).…”