Obsidian is a naturally occurring volcanic glass formed when lava cools rapidly without crystallization. It's typically dark in color, ranging from black to deep brown, and often displays a glossy, reflective surface. This glassy texture is due to its lack of crystalline structure, making it different from most other minerals.
Obsidian Open Bezel Pendant
Obsidian (/əbˈsɪdi.ən, ɒb-/ əb-SID-ee-ən ob-)[5] is a naturally occurring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock.[6]
Obsidian is produced from felsic lava, rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. It is commonly found within the margins of rhyolitic lava flows known as obsidian flows. These flows have a high content of silica, granting them a high viscosity. The high viscosity inhibits diffusion of atoms through the lava, which inhibits the first step (nucleation) in the formation of mineral crystals. Together with rapid cooling, this results in a natural glass forming from the lava.[7]
