What makes a jewelry finish “white silver”, “dark patina” or “vermeil”?
I use different techniques with my designs to enhance the unique look of each piece. The Vertebrae Collection for example is finished to near white like a sun bleached bone. To achieve the finish I use a process called Depletion Silvering to create a layer of pure or fine silver on the surface. The pure silver is very white in appearance and before polishing has a soft white surface texture created when the copper in the Sterling Silver alloy is removed.
An ancient technique more commonly know when used with gold as in Depletion Gilding, Depletion Silvering works on a molecular level. Sterling Silver is an alloy of pure silver and copper a combination that makes the metal strong and malleable. Pure silver like pure gold is resistant to oxidation and mild acids. Copper on the other hand will dissolve when exposed to common acids like table salt or sodium bisulphate commonly used by jewelers to remove copper oxidation after heating during fabrication. The black oxidation on the surface is copper; removing the copper in a mild acid bath repeatedly (10 or more times) leaves more of the pure silver on the surface of the jewelry thus giving it a fine silver “skin”. The copper molecules that dissolve into the acid leave a slightly porous surface enhancing the” boney white” look I like for the Vertebrae Collection.