Since it's born out of molten rock, obsidian is only found in volcanic regions of the world, including in parts of the United States, such as the Mountain West, Southwest, California, Oregon, and ...

That’s because obsidian is pretty unstable as far as rocks go; over time, the silica molecules within it end up rearranging into a more organized fashion, a process known as devitrification.

Obsidian nodules and flakes have a smooth, glassy texture and sharp edges. At a microscopic level, obsidian flakes can be sharper than instruments made of surgical steel.

I walked a mile of the PCT along some of the most incredible high-country scenery I have ever encountered. The trail led through shiny obsidian rock and skirted the creek and several small ponds.

In this Sept. 8, 2016 photo, Obsidian Trail cuts through lava rock on the way to Obsidian Falls near Sisters, Ore. The Obsidian Trailhead provides access to the Pacific Crest Trail and to loop ...

A piece of obsidian rock sits on display in the Smithsonian Institution in Washington, D.C. William Healey Dall collected the rock in the 1860s near the Nowitna River in Interior Alaska.