Stealth Sterling Silver Rounded Box Chain 2.5mmThese rounded box chains are made with Stealth Sterling Silver and are available in 18, 24, 30 and 36 inch lengths. Diameter: 2. 5mm Clasp type: Lobster The Black Silver or Stealth Sterling, as I like to call it, is made with Sterling Sliver process though patination. I use simple chemistry which speeds up the oxidation process of the silver and turns it black. The black color is not permanent, eventually the object will adapt to the wearer and the