Obsidian

Obsidian is a naturally occurring volcanic glass formed when lava cools rapidly. It is typically dark in color, often black or greenish, and has a smooth, shiny surface. Used by ancient civilizations for tools and weapons due to its sharp edges when fractured, obsidian is also popular in jewelry and decorative items today. Its unique appearance and properties make it prized in various cultures. Additionally, obsidian can provide insights into geological processes and is studied in fields such as archaeology and geology.