14k Yellow, White or Rose Gold Ball Stud Earrings with Jellybacks - 2, 3, 4, 5, 6, 7, 8, 9, 10, 12mm Unsure what size earrings to buy? 5mm is the perfect size that will look great on most people. These earrings are made of solid 14k gold and are stamped "14k". These beautiful and well-made earrings are perfect to suit any occasion. The jellybacks offer added security over traditional earring backings as well as a lower price. Please note that the post measures 8mm, which is shorter than a standard post.