Trustmark 925 Sterling Silver 4mm Natural Blue Lapis Lazuli Ball Stud Post Earrings Made with Natual Lapis Lazuli Features our petite 4mm size which is about 1/6 of an inch. Metal Components:Solid 925 Sterling Silver. Hallmarked. Professionally hand-set in our own US studio. Style or Setting:Cup post for Pierced Ears.