Spiderweb Obsidian

Spiderweb obsidian is a type of volcanic glass that is formed when lava cools quickly. The distinctive pattern seen in spiderweb obsidian is created by mineral inclusions, which resemble the delicate threads of a spiderweb.

The mineral inclusions are typically made of feldspar or cristobalite, and can be black, brown, blue, grey, or white, creating a striking contrast against the dark blue-black background of the obsidian.