Great example of rare fire obsidian from Glass Buttes, Oregon. This decent-sized rough has both side ground down with 600 grit to within 1-2 mm of the surface of the fire layers. The main face is a concave face that will show nice after finished and with 1-2 lights shone directly on it's its surface at eye-level to the viewer. The other side is domed but is lower grade and is much less bright.

This might seem obvious, but it still needs to be said - the video and photos in this auction show the rock both wet and dry and in direct sunlight.

Oddrox: Fire Obsidian Faced Rough Stone 280 Carats, - magnetite