Early Medieval gombiky from the “Lumbe Garden” cemetery, Prague Castle

Abstract

This paper presents a typological and technical study of gombiky (hollow spherical pendants) from the excavations of the Early Medieval cemetery "Lumbe's Garden" in Prague Castle, in which the state elite linked to the early Czech princely environment was buried. The goal of the research is the characterization of the material and the manufacturing techniques. The Gombiky were characterized by optical stereomicroscope (Olympus SZ60), X-radiography, scanning electron microscopy (SEM), supplemented by electron microanalysis (EDS), and metallographic examination. Replicas were manufactured by a goldsmith.The typological and material study evidenced five main types of gombiky, according to the shells' shape, the decorative technique, and the material.Most of the pieces were of unalloyed copper or copper alloys with a small amount of tin (ca. 2%) and were fire-gilt. The different components are soldered with an Ag-Cu hard solder. A pair of gombiky was made of almost pure silver with ca. 2% of copper. A gold alloy was also identified. The gombiky are decorated by chasing and repoussé, but also with granulation and filigree work, glass cabochons, and gilding.

Fire gilding investigation on early medieval copper-based jewellery by focused ion beam (FIB) on FEG-SEM

“…1a) its construction is typical of Bohemian pieces, as shown from X-ray radiography (Fig. 1e): a two-hemisphere body and a suspension system made of three components (Ottenwelter et al, 2014;Ottenwelter et al, 2017;Ottenwelter et al, 2020): a loop, a clamp and a ring, in this case also including a small pellet inside the soldered hemispheres. The gombik was highly fragmented when excavated.…”

“…The study focuses on central European gilded copper jewellery, for which fire gilding was largely applied (Ottenwelter, in press). It concerns the fire gilding layers of specific archaeological artefacts found in Bohemia (Lumbe Garden cemetery at Prague Castle): gombiky (spherical hollow pendants) and medallions, characteristic pieces of the elite jewellery from the 9th and 10th centuries AD, detailed in previous studies (Ottenwelter et al, 2014;Ottenwelter et al, 2017;Ottenwelter et al, 2020;Ottenwelter, in press). The use of FIB FEG-SEM allows crosssections to be made and observations performed in situ within the SEM (Johnson et al, 2012;Chiavari et al, 2015;Masi et al, 2016, Masi et al, 2017.…”

Research on chemical soldering in early medieval jewellery: The case of lunula‐type Viking age ornaments

“…Their studies included a series of experiments in which they recreated the Great Moravia goldsmith's workshop (Čáp et al, 2011; Dĕd et al, 2016). Other important works concerned jewelleries from the Lumbe Garden cemetery at Prague Castle (Ottenwelter et al, 2014) and Great Moravian jewellery from the Pohansko site (Macháček et al, 2016). In the aforementioned Czech studies, technological analyses were carried out with scanning electron microscopy using energy dispersive X‐ray spectroscopy (SEM‐EDS).…”

“…In the aforementioned Czech studies, technological analyses were carried out with scanning electron microscopy using energy dispersive X‐ray spectroscopy (SEM‐EDS). However, as invasive tests were possible, measurements were additionally carried out on the cross‐sections of the objects, which allowed minimization of corrosion‐related determination errors (Dĕd et al, 2016; Kolářová et al, 2014; Ottenwelter et al, 2014). Due to Polish museum requirements, no invasive tests were possible.…”

Technological characterisation of early Medieval gilded copper hollow pendants (gombiky), from Mikulčice (Moravia) and Prague Castle (Bohemia)

“…Most studies have focused not only on the typology of gombiky based on size, shape, decoration and their possible origin (Hrubý 1955;Dostál 1966;Pavlovičová 1996;Klanica 2006;Macháček et al 2016), but also on their occurrence in graves and their hypothetical function (Klanica 1970;Chorvátová 2008;Krupičková et al 2019). Several technical studies have been performed to characterise their material composition by surface analysis, mostly by X-ray fluorescence (Smetánka and Štverák 1992;Smetánka and Staňa 1996;Profantová and Frána 2003) and more recently by SEM/EDS (Kavánová 2009;Ottenwelter et al 2014;Ottenwelter 2016;Ottenwelter et al 2017;Hasil et al 2019). Innovative experimental approaches have focused on the different steps involved in their manufacture (Čáp et al 2011;Barčáková 2014; Barčáková et al 2014).…”