Venice. Glassmaking was moved by decree to the island of Murano to reduce the risk of fire in Venice, which at the time was largely built of wood. Chioggia specialized in salt production. The glassmakers’ guild split into glassmakers and crystal workers, as the latter soon began making spectacles. Another Venetian specialty was large window panes. For example, in 1285 and 1305, enormous panes of glass were supplied for a lighthouse in Ancona. Venice, in fact, had the main raw materials needed: silicates from the lagoon sands, clays for kilns found in the Venice area, firewood from Friuli and Istria, and soda ash (sodium carbonate) imported from Syria (obtained by burning algae), which made Venetian glass (marine glass) superior to Nordic glass (forest glass), which was made with potash (potassium carbonate) obtained by burning hardwoods.
