Chemical composition of archaeological glasses from Prague Castle (Czech Republic) from the period 1650-1800 determined by electron probe microanalysis and laser ablation inductively coupled plasma mass spectrometry

This is the first detailed study using 55 major, minor and trace elements in archaeological glass from the period of 1650-1800 from two cesspits at Prague Castle, the Czech Republic. These glasses were obtained during archaeological excavations in 1920s. Among the forty analyzed samples, a single specimen of the so-called high-lime low-alkali glass was identified; such materials are much more widespread in western Europe than in the territory of the Czech Republic. Other samples represent potassium glass among which three major types can be distinguished: wood ash glass, potash glass and potassium crystal-clear glass. This study confirms that an important turning point in glass technology occurred in the latter half of the 17th century. Chemical composition of the glass excavated from cesspits at Prague Castle overlaps that of glass recovered from ruins of 17th- to 18th-century buildings in Lisbon. This opens a possibility that the finds in Portugal represent imports from Bohemia.