This premium Volcanic glass is a product of rapid cooling magma. Like most glass, it has a state of matter between the array of a crystal and a disordered array of gas.
This "Zombie Glass" made from Obsidian can refer to the interstitial, or matrix, material in fine grained volcanic rock. This can also refer to any of several types of igneous rocks. Most commonly, it refers to obsidian, a rhyolitic glass with a silica SiO2 content.