Natron-type glass

Natron-type glass uses mineral natron as its flux; it was the basis of glassmaking in the traditional centres of Egypt and the Levant in Roman and late antique times. ³ Scholars divide Mediterranean natron glass into ten major compositional groups, each the likely output of a discrete primary centre active for a limited period, on the assumption that its composition reflects the silica source. ^{3 4}

Natron glass production continued well into the Islamic period; the shift to plant-ash glass came only at the turn of the ninth century in Syria-Palestine, and considerably later in Egypt and the western Islamic world. ¹ In Egypt it was still made until about 870; the last glass weight of "Egypt 2" composition dates to the first year of Ahmad ibn Tulun's governorship (868). ^{5 2} Nadine Schibille links this to restrictions on natron extraction imposed by the director of finances Ibn al-Mudabbir, and explains the late transition in Egypt partly by its natural natron deposits. ²

Schibille and colleagues analysed 908 tesserae from the mosaics of the Great Umayyad Mosque in Damascus, whose main group she calls "Egypt 1Ax", an Egyptian natron glass. ^{5 6} She sees in this the steady demise of Levantine natron glassmaking against a still-flourishing Egyptian natron industry. ⁷