Sapphire blue and green fire opal 16 gauge cartilage earring, monroe, tragus or helix piercing set in IP black. 316L surgical steel plate black barbell piercing is 16 gauge with a 5/16" long post. The post of this opal earring is internally threaded and the top opal gem unscrews from the post. Genuine opal stone is used in this gold plated 316L surgical steel setting, and is available in 3mm, 4mm or 5mm stone, or one in each size (a set of 3). Please choose your stone size when checking out. Will arrive in a gift box.