Obsidian

Obsidian was used for many kinds of cutting tools and weapon points, and was by far the raw material of choice for making chipped stone tools at Çatalhöyük - but ironically, obsidian is not a type of stone at all! Obsidian is a natural volcanic glass and is thought to have been brought to Çatalhöyük from nearby mountain sources such as Hasan Dag. While stone tools may seem primitive and crude to us, the edge of an obsidian blade is actually sharper than a modern medical scalpel. This is because unlike stone, glass is made of pure silica instead of various mineral grains - so when obsidian is fractured it can create an edge with a thickness of only one molecule of silica!