The volcanic islet of Yali, north Dodecanese, is a palimpsest of ancient occupations which go backwards as early as the Final Neolithic (4th millennium BC). Huge amounts of Neolithic pottery are dispersed across the entire island, and are not only clustered within the extent of certain spots with structures. The Neolithic habitants of the island may have been attracted by various subsistence resources, but also very significantly by the sources of the local obsidian. Yali obisidan is reported to have been of limited use in the Neolithic and the Bronze Age of the Aegean and Crete, compared to the Melian obsidian across the Aegean; this may be due to the facts that is more fragile, contains pockets of volcanic ash, is transparent in color and cannot be knapped and retouched the same way. However the Neolithic craftsmen did produce tools from some of the outcrops.
Macroscopic examination of the Neolithic coarse wares from the island has shown that the local obsidian is also present in some of the fabrics, which is a confirmation of their local provenance. Preliminary sampling and petrographic analyses that we have carried out, have confirmed that obsidian was added as temper to the processed clay than being part of the raw material. A series of other fabrics that are consistent with the local materials but contain other temper, show that the use of obsidian was apt to a certain decision by the potter. Variations and specifications of the evidence are still within future research.