Minnesota Agate with Eye set in Textured Sterling Silver.
This mysterious agate characteristic is believed to be formed when most of the silica gel drains from the cavity, leaving only a droplet that “beads up” on the inside wall of the cavity. This droplet crystallizes into solid chalcedony “eyes”. In some cases, crystal growth will continue from this droplet in a manner similar to the formation of stalactites in caves. Later, the pocket fills in with the usual deposition of chalcedony microcrystals.