processes. Due to its physical properties, rock crystal was frequently used as a lithic raw material for the production of tools and weapons in prehistoric times. Recently, the first mining sites where the material was aquired in large quantities, were discovered. One of them is situated near Eggishorn Mountain in the Upper Valais (Switzerland) at an elevation of 2600 m above sea level. The archaeological finds and features date to the Early Mesolithic (almost 10,000 years ago) and to a younger phase of the Neolithic.

The talk presents the results of a petrographic characterisation of the material occurring at the investigated site. It provides a description of the fluid inclusions within the quartz crystals and an overview over the related mineral paragenesis.
This gives interesting new insights into the formation of the analysed fissure and allows comparing rock crystal artefacts found in other archaeological sites to this particular source. The results form the basis for further investigations concerning mobility patterns and trade networks in the past.