The Imperial Crown of the Holy Roman Empire, Part I: Photoluminescence and Raman spectroscopic study of the gemstones

Author(s)
Lutz Nasdala, Teresa Lamers, H. Albert Gilg, N. Chutimun Chanmuang, Martina Griesser, Franz Kirchweger, Annalena Erlacher, Miriam Boehmler, Gerald Giester
Abstract

The Imperial Crown of the Holy Roman Empire is not only a unique and outstanding symbol of European history, it is also one of the most significant works of Western goldsmiths' art from the High Middle Ages. However, little is known about the gem materials it contains. As part of an interdisciplinary research project led by the Kunsthistorisches Museum Vienna in Austria, the 172 gemstones in the crown were all conclusively identified for the first time using (non-destructive) photoluminescence and Raman spectroscopy. They include 71 blue sapphires, 50 garnets (22 almandines, 22 pyrope-almandines, five pyropes and one grossular), 20 emeralds, 13 amethysts, four chalcedonies and three spinels. In addition, 11 glass imitations of various colours were identified. Raman spectral details and inclusions in the garnets support their assignment to garnet types previously found to be used in antique and early medieval jewellery. The large red spinel in the centre of the crown's front plate is presumably part of the original crown and, thus, is one of the earliest-known spinels in a historic object, yet it yielded spectroscopic evidence of having been heated.

Organisation(s)
Department of Mineralogy and Crystallography
External organisation(s)
Kunsthistorisches Museum Wien, Technische Universität München, WITec Wissenschaftliche Instrumente und Technologie GmbH
Journal
Journal of Gemmology
Volume
38
Pages
448-473
No. of pages
26
ISSN
1355-4565
DOI
https://doi.org/10.15506/JoG.2023.38.5.448
Publication date
01-2023
Peer reviewed
Yes
Austrian Fields of Science 2012
105116 Mineralogy
ASJC Scopus subject areas
Geochemistry and Petrology
Portal url
https://ucrisportal.univie.ac.at/en/publications/cce5cd8c-fe19-4b58-a5d2-42e99f43632f