Obsidian Sphere Ball Mexican Stone Gemstone Mineral

Description OBSIDIAN SPHERE This is the polished golden obsidian sphere. Diameter 1.9″ (4.9cm). Weight – 5oz (141 grams). Origin: Mexico. Some information about obsidian: Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It produced when felsic lava extruded from a volcano cools rapidly with minimal crystal growth. It commonly found within the margins of rhyolitic lava flows known as obsidian flows, where the chemical composition (high silica content) causes a high viscosity, which, upon rapid cooling, results in a natural glass forming from the lava. The inhibition of atomic diffusion through this highly viscous lava explains the lack of crystal growth. Obsidian is hard, brittle, and amorphous; it therefore fractures with sharp edges. In the past, it used to manufacture cutting and piercing tools, and experimentally as surgical scalpel blades.