SilverSpeck E11523AP 4 mm. Sterling Silver Genuine 0.6 Carat Apatite Round Stud Earring These stud earrings feature 4 mm. round apatite stones. The earrings are crafted of sterling silver and are secured with a post and friction backs. Total gem weight is 0.60 ct. Metal Type - Sterling-Silver Metal Stamp - 925-Sterling