The chemical analysis of obsidian from the Anatolian site Cafer Höyük shows two different compositions. In addition, prospections in the Bingöl-Solhan region revealed several natural sources of obsidian. Analysis of samples from one source (Çavuslar) showed not one, but two chemical compositions. These same two types are present in the obsidian at Cafer Höyük. It therefore appears that Çavuslar was the obsidian source used by the prehistoric inhabitants of Cafer Höyük and that a single source can contain several types of obsidian.