Thundereggs

A thunderegg is very similiar to a geode, and the two are often confused. A geode is formed from sedimentary processes. A thunderegg is formed as a trapped gas pocket, in a rhyolitic lava flow. Over time, water rich in minerals seeped into these pockets. Sometimes they were paritally filled, creating a geode-like effect; while others filled completely. The ugly outer shell masks the true beauty hidden within.

The term "thunderegg" refers to the name given to these stones by the local indians. These were found eroded out of rock after rainstorms, so it was believed that angry gods tossed these stones around during thunderstorms. There are over 178 locations for thundereggs within the USA.

Below are the categories of thundereggs we offer.
These were personally mined from several locations in the USA.