Glass in the Middle East and Western Europe at the End of the First Millennium CE, Transition from Natron to Plant Ash Soda or Forest Glasses

Overseas imports on the Blue Nile: Chemical compositional analysis of glass beads from Soba, Nubia

“…East of the Euphrates this glass tradition survived and glass of the type was made by Sasanian and Islamic glassmakers between the third and 17th centuries CE (e.g., Mirti et al, 2008, 2009: Veh Ardasir, Iraq, third–seventh centuries CE, Sasanian glass; Henderson et al, 2016: Nishapur, Iran, ninth–10th centuries; Phelps, 2016; Henderson et al, 2016: Raqqa, Syria, eighth–11th centuries; Schibille et al, 2018: Samarra, ninth century). The first Islamic soda ash glass in the Levant dates to the end of the eighth century, whereas in Egypt it does not occur before the 10th century (Gratuze et al, 2021; Gratuze & Barrandon, 1990; Henderson et al, 2016; Phelps, 2016, 2018).…”

The emperor's new glass: The introduction of Carolingian wood ash glass in North Sea trade

“…A recycled nature of the WA‐2 glasses is implied by the observation of Na 2 O/Al 2 O 3 ratios near 1, which cannot solely be explained by plagioclase in the sands (Wedepohl et al, 1997), and elevated Na 2 O concentrations are thus likely caused by remelting in the presence of small amounts of natron glass (Figure 6c). Elevated Na 2 O concentrations in wood ash glass have previously been ascribed to mixing with natron glass during recycling at nearby Haithabu/Hedeby (Kronz et al, 2015) and at a ninth‐century glass workshop in Meru, France (Gratuze et al, 2021). Here, intense recycling led to intermediate mixtures of natron and wood ash‐type glasses that span the entire compositional range between the two glass types.…”

“…From the end of the Roman period (ca. 400 CE), the supply of glass for the production of vessels, windows, and beads in Northern and Western Europe was increasingly dominated by recycling of Roman‐period natron glass, supplemented by importation of contemporary glass types from the Eastern Mediterranean (e.g., Barfod, Feveile, & Sindbæk, 2022; Gratuze et al, 2021; Wedepohl, 2003). In the second half of the eighth century CE, this supply was supplemented by the earliest attested native production of raw glass in Western Europe, based on the development of a new technology using quartzite or sand with low lime mixed with wood ash, typically from beech (Van Wersch et al, 2016; Wedepohl, 2003 among others).…”

Le recyclage du verre au temps des Romains, des Francs et des Byzantins

“…De nouveaux procédés sont donc inventés en sollicitant davantage des ressources locales. C'est ainsi qu'apparaissent au cours de la seconde moitié du VIII e siècle des verres fabriqués à partir d'un mélange de sable et de cendres de plantes forestières [5]. Des espèces végétales telles que le chêne, le hêtre ou la fougère fournissent de la potasse et de la chaux qui jouent les rôles de fondant et de stabilisant dans la fabrication du verre.…”