Catseye chrysoberyl, or simply catseye, is a phenomenal variety of chrysoberyl that exhibits chatoyancy. Chatoyancy occurs in cabochon cut gems that contain a high density of parallel fibrous inclusions. In the case of chrysoberyl, the inclusions are rutile. Light reflects perpendicular to the direction of these inclusions giving the stone its namesake appearance. Some catseyes will appear to exhibit two different colors on either side of the “eye”. This phenomenon is known as the “milk and honey” effect. Catseyes that are transparent to translucent are sometimes referred to as cymophane. Catseyes occur in golden yellow to an unusual electrifying green-yellow to green to brown. Catseyes are designated as the 18th wedding anniversary gem.