obsidian

/əbˈsɪdiən/
noun
  1. A hard, dark, glass-like volcanic rock that forms when lava cools quickly. It is often black and used to make sharp tools or jewelry.
    • The necklace was made of polished obsidian beads that gleamed like dark mirrors.
    • Volcanic eruptions can produce obsidian when the lava cools too fast to form crystals.
    • Ancient people used obsidian to make arrowheads and knives because it can be chipped into very sharp edges.
adjective
  1. Made of or resembling obsidian; very dark, shiny, and smooth like the volcanic glass.
    • She wore an obsidian ring that caught the light with a deep, glossy shine.
    • The cat had obsidian eyes that seemed to glow in the dark.
    • The sculpture had an obsidian surface, polished to a mirror-like finish.
What does "obsidian" mean? | whatsthatwordmean | whatsthatwordmean