Obsidian is a glassy rock formed when lava cools rapidly; it fractures like glass to produce extremely sharp edges — and is just as brittle. In the Near East, two great source regions stand out: eastern Anatolia (Bingöl, Nemrut, Süphan, Acıgöl) and central Anatolia (Cappadocia). Each volcano's obsidian carries a unique trace-element fingerprint; today, X-ray fluorescence can identify which volcano a tool came from with ease.

The result is striking. From around 12,000 BCE onward, Anatolian obsidian is routinely found hundreds of kilometres from its source — in the Levant, in Mesopotamia, even on Cyprus. Green Cappadocian obsidian at Jericho; Bingöl glass on the coast of Palestine; Nemrut stone in northern Mesopotamia. This is not accident but a systematic flow. Agriculture had not yet fully settled, cities had not yet been built, the wheel had not yet been invented — and already an exchange network ran between hunter-gatherer communities.

Obsidian is not only a raw material; it is a signal molecule. A blade in someone's hand is the tangible trace of a relationship — direct or indirect — between one group and another. Long-distance exchange is a precursor to the social infrastructure of the Neolithic transformation that follows: settlement, agriculture, monumental architecture, specialisation.