Recently, I spent a weekend outside Bend, Oregon. I dug for Oregon Thundereggs, which are Oregon’s state mineral.
Thundereggs are like geodes, except they’re filled with minerals like agate, jasper, and opal. They form within layers of volcanic ash.
I dug for mine at Richardson’s Rock Ranch, which was about an hour outside Bend.

To get them out of the ground, I used a sledgehammer, a rock chisel with thumb guard, and a plastic brush to remove debris.
I dug in three beds at Richardson’s Rock Ranch (including the Priday Agate Beds), and found thundereggs filled with banded agate, plume agate, and common opal.
While I waited for my thundereggs to be cut, I wandered around and found a nest of barn swallows under a porch roof.

Check out the photos below of the best thundereggs I dug up!