Obsidian

Definition

Obsidian is a naturally occurring volcanic glass that forms when molten lava cools rapidly. It is known for its smooth, shiny appearance and sharp edges.

Related terms

Flint: A type of hard stone used by early humans to make tools and weapons.

Pumice: A light-colored volcanic rock with lots of air pockets, often used as an abrasive material.

Basalt:

Another type of volcanic rock that is commonly found in oceanic crust and has a dark color similar to obsidian.