The role of obsidian analysis in understanding the earliest trade and contact within the Near East is well established; the two main sources of such obsidian are in Central Anatolia and Eastern Anatolia. Data produced from neutron activation analyses of obsidian from Central Anatolia are presented. Previous studies have concentrated upon archaeologically excavated obsidian with only limited quantities of geological obsidian being available. The field work presenting this analytical program was thus as detailed as could be achieved, with samples collected extensively over both short and long distances, and covering most of the known sources of obsidian in the area. Following appropriate statistical treatment the analytical groupings revealed two main features: a large number of sources of obsidian, and, analytically, remarkably well-differentiated sources. Analytical consistency within any given source is striking -- the potential for pinpointing sources used in antiquity is thus considerable. -- AATA