A collection of obsidian and other rocks from Glass Buttes rockhounding site. Visitors are allowed to collect up to 25 pounds of rocks per day and 250 pounds per year, per person at designated sites ...

Glass Buttes Obsidian is a black, brown, green, or mottled black-brown obsidian. The color becomes dull when heat-treated. When weathered it becomes light gray. It has a vitreous texture. Deposits ...