The Waldenburg Beakers and Johann Kunckel: Analytical and technological study of four corner-cut coloured glasses

Abstract

The provenance of at least five of seven variously coloured glass beakers in the collection of the Naturalienkabinett Waldenburg (Saxony) indicates their relation to the famous glass chemist Johann Kunckel. The technological characteristics of four corner-cut glasses, which show a ruby-rose, transparent blue-green, transparent dark purple, and an opaque striated brownish-red colour are described. Crizzling phenomena, cracking due to frozen strains, and inhomogeneous colouring were closely examined with a light microscope and under a short-wave ultraviolet lamp. Combined simultaneous particle-induced X-ray emission and particle-induced gamma ray emission analysis conducted at the Helmholtz–Zentrum Dresden–Rossendorf allowed detection of all glass constituents from lead down to boron in concentrations above approximately 0.01% (weight percentages of elemental oxides). Different types of potassium-rich crystal glass with varying amounts of calcium, arsenic, and lead were found. There is evidence for the use of highly refined raw materials and the addition of various ionic and colloidal glass colorants. The Waldenburg beakers seem to be early examples of Kunckel's experimental efforts to establish elevated standards for the production of luxury glass in northern Europe, as additionally supported by accounts in his publications from the years between 1678 and 1716.

Keywords:

• Kunckel
• Linck
• Coloured crystal glass
• Glass cutting
• Wheel engraving
• PIXE Analysis
• Frozen strains
• Crizzling
• Ars Vitraria Experimentalis

Acknowledgements

For individual assistance the authors express their gratitude to Ralph Zenker and Ulrike Budig, Waldenburg; Jerzy Kunicki-Goldfinger, Warsaw; Christian Theuerkauff and Anna-Elisabeth Theuerkauff-Liederwald, Berlin; and Dirk Weber and Michael Korey, Dresden.