obsidiaan

noun
  1. Obsidiaan is a Dutch term for 'obsidian,' a naturally occurring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is known for its smooth, glassy texture and is often used for decorative purposes and in jewelry. noun
    The ancient civilizations used obsidian to make sharp blades and arrowheads.
    Obsidian is often used in modern jewelry for its striking appearance.