Love this beautiful color of blue from this very magical stone. The materials are oxidized sterling silver, fine silver bezels, 18k, Volcanic Blue Opal Petrified Wood from Indonesia. Please note the bezels can take on a golden hue from the oxidation process. For care please do not use a polishing cloth as that can alter the patina, you can swish in warm sudsy water, rinse and dry. The size is 2 7/8″ x 5/8″