MN Agate with Eye

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.