This ring is made with bright cobalt blue sea glass set in a fine and sterling silver bezel cup. The ring band is made with a round sterling wire. This is natural sea tumbled sea glass, also known as beach glass. A friend of mine has named this color "bluest thing ever," deeming that "cobalt" is not a good enough description. The silver backing to the bezel brings out the bright, deep color of this glass. Due to the fragility of sea glass, this ring cannot be resized and is only available in size 9. The glass is a completely unique shape that is approximately 6mm wide and 13mm long. Over time, sterling silver rings will oxidize and appear to darken in color. To keep your ring clean and remove the oxidation, wipe gently with a silver polishing cloth. Do not use liquid jewelry cleaner - this risks damage to the glass.