Thundereggs are rough spheres, most about as big as a baseball and they contain centers of chalcedony in the form of agate, jasper, or opal.
Thundereggs are rough spheres, most about as big as a baseball. They contain centers of chalcedony in the form of agate. They contain centers of chalcedony in the form of jasper. They contain centers of chalcedony in the form of opal.