Obsidian Sphere

Obsidian Spheres are items from Ghostscape 2: The Cabin. They are found by searching the appropriate areas of ground with a metal detector (which is odd, since obsidian is not metallic). There are five spheres in total, and they can be placed in the sockets of the pentagram outside the central cave in a series of patterns to raise the stone door blocking access.

Appearance
The Obsidian Spheres are, as the name suggests, smooth black orbs crafted from obsidian, a dark volcanic glass.