Origin of red garnets in early medieval jewellery in the Netherlands.
Garnet is incorporated in much early medieval jewellery found in what we now know as The Netherlands. Research into the chemical composition shows that this mineral was mostly mined in India.
Measuring points on a fibula
In the early Middle Ages, clothing accessories of the elite such as belt buckles and fibulae (clothing fasteners) were often richly decorated with so-called cloisonné inlay. This involved inlays of slices of garnet, a red semi-precious gemstone, being laid in cells, often made of thin gold walls.
Different types of red garnets were used, including almandine and pyrope, whose origin can be determined from their chemical composition. The aim of this research was to establish whether different materials can be linked to different parts and spheres of influence in the early Medieval Netherlands: the west (English influence), south (Franken), north (Frisians) and east (Rhineland).
Using the research techniques available at RCE it was established that the jewels are indeed inlaid with almandines and pyropes. Analysis with the so-called PIXE technique at the C2RMF (Centre for Research and Restoration of the Museums of France) particle accelerator in Paris was necessary to learn their origin. The gemstones could be classified into several groups based on the analysis results.
With the largest group of gemstones (which was also most represented in the majority of objects), the composition was found to correspond with almandine from Rajasthan in India. Single almandines of another type found in India, Sri Lanka, Madagascar and East Africa were also identified in many jewels.
Two fibulae from the Frisian region were shown to be inlaid with pyropes: one with chromium pyropes, probably from Bohemia, the other with gemstones that probably came from Portugal. But fibulae and buckles with almandine were also found in the Frisian region, such as the famous Wijnaldum fibula.
Another project involving research into red garnets was 'Reviving Rhenen'. The burial field in rows of Rhenen was excavated in 1951, but until recently the information was unknown and inaccessible to scholars and public. The publication of a catalogue of the early medieval cemetery was the objective of the 'Reviving Rhenen' project. The garnets and textiles from the burial field were investigated by the RCE.