Product Details

These thundereggs are from Costilla County, CO. The interiors may include the following: chalcedony, agate, moss agate, quartz (mostly druzy, but small crystals are possible), birdseye/orbicular rhyolite, brecciated thundereggs (interiors containing rhyolite and perlite, with some chalcedony or agate), flow banded rhyolite, common opal (rarely hyalite) Some of these thundereggs will fluoresce green under shortwave UV, but don't react much under longwave UV.