Complex sentence: Excavation of Anglo-Saxon sites has produced some evidence for limited glass working in the form of crucibles for melting glass, glass debris and furnaces, although, to date, no furnaces have been found associated with crucibles or glass working debris, or vice versa.
Split into simpler sentences: Excavation of Anglo-Saxon sites has produced some evidence for limited glass working in the form of crucibles for melting glass, glass debris and furnaces. Although, to date, no furnaces have been found associated with crucibles or glass working debris, or vice versa.