Lance Wakeling - USB Edition with Subida al Cielo (sold out)

Obsidian is a volcanic glass. When polished its surface becomes reflective. It fractures easily, with each break creating sharp edges. Over time, obsidian is broken down by contact with water. And therefore, none has been found that predates the Cretaceous age, a geologic period marked by massive extinctions and huge oil deposits. Using each volcano's unique fingerprint, the origin of obsidian artifacts can be traced around the world. The Aztecs used obsidian for sacrificial knives. Today, it is used for experimental scalpel blades – the sharp edge of which can be as thin as three nanometers.