Abstract The Bronze Age tell settlement of Százhalombatta-Földvár is one of the most detailed studied ancient sites in Central Europe dating from c. 2000–1400 BC. It is located on the right bank of the Danube, south of Budapest. Annual archaeological excavations have been conducted for over 25 years as part of the “Százhalombatta Archaeological Expedition (SAX)” project. Finds of vitrified clay—a molten glass phase that contains unmolten material—were available for investigations. The glass phase is composed of approximately 8.5 wt% K 2 O and 42 wt% SiO 2 as well as Na 2 O, CaO, MgO, and Al 2 O 3 . All these components can be found in ashes after combustion of plants and animals. It is supposed that temperatures slightly higher than 700 °C are sufficient to form vitrified clay. In fireplaces such temperatures can be achieved easily.
Vicze et al. (Mon,) studied this question.