Where can obsidian be found?

Question

Where is obsidian found?Is it typically found on the surface or underground? If underground, how far under (meters or feet would be perfect)?Also, is it found everywhere on Earth, or just in areas where volcanic activity is (or was recently) high?

Answer 1

Igneous rocks that form at the surface are called volcanic or extrusive. Whereas igneous rocks that form in the subsurface are called plutonic or intrusive. Obsidian is formed at the surface of our planet and is, therefore, called a volcanic or extrusive igneous rock. Its texture is classified as glassy. The larger the grain size of minerals in a rock, the longer it takes for the mineral to cool down and solidify. Obsidian cooled so fast that you are unable to see individual minerals with the naked eye, indicating it cooled very fast in geological time. Obsidian would only be found in areas that have volcanic activity.