Our Niobium Cabochon Stud Earrings feature a variety of gemstone cabochons in a variety of colors and sizes in Argentium Silver bezel settings on handmade pure Niobium posts. We make the posts a standard length, but can make them a custom length for your ear lobe comfort if desired. Pure Niobium is sometimes denoted as 999 Niobium. It is naturally nickel free, chromium free, and cobalt free. Niobium is ultra comfortable and often people remark that they forget they are even wearing earrings while they are wearing Niobium. Argentium Silver (or Argentium Sterling Silver) is 92.5% silver, 6.3% copper, and 1.2% germanium. It is slow to tarnish so requires less frequent polishing than Sterling Silver. Argentium Silver is nickel free and is very comfortable resting on the front of your ear lobe. These stud earrings come with Commercially Pure Grade 1 Titanium ear nut earring backs.