,...new sterlings that do not contain copper...>

As far as I know, the term "Sterling" denotes by law, in the U.S. and Great Britain at least, an alloy containing 92.5% silver and 7.5% copper. If you change the copper for a different alloying ingredient, you have a silver alloy alright, but not one you can call "sterling."

Most of the oxidizers (patinators) like liver of sulfur that work on sterling, work on the copper content. Fine (99.99+%) silver doesn't naturally oxidize. Copper, on the other hand, is a highly reactive metal and oxidizes readily. It also forms other compounds such as cupric cloride, copper sulfate, etc, pretty readily, opening the door to a wider range of colors. Not all of them are stable, though.

You might try one of the green patina formulas on the copper, using it sparingly and cool, and it may not affect the sterling as much. Be prepared for surprises, and don't be afraid to pickle it clean and start over if you don't get what you like.

From what I have found, sterling silver is 92.5-per-cent silver and 7.5-per-cent some other metal, which until lately, has been copper. However, other alloying agents, such as "Argentium", germanium, and even tin have been used as part or all of that 7.5-per-cent. The resulting allow remains "Sterling", but in a variant form.

You are somewhat correct.

"Sterling Silver" is 92.5% silver and 7.5% alloy metal, usually (traditionally) copper. It is still generally copper; that has not changed over the years.

During the 1990s, Peter Johns experimented with other alloying ingredients, in an effort to eliminate some of copper's undesirable traits, primarily firescale. It was found that the addition of a small amount of germanium to the copper alloying ingredient eliminated the tendency of the resulting sterling to create firescale when heated. The resulting alloy was patented and trademarked as "Argentium Sterling", a proprietary product.

The term "argentium" is a made up trade name, and is not an element as you suggested.

Rich

You might try a technique borrowed from the textile people. They use wax to prevent dye from penetrating areas in a process called batik. Wax also works just fine as a stop or resist in some electroplating processes. Floor wax should work just fine. candle wax may be just a little brittle. Coat the areas you do not want to patina.play around with the thickness of the floor wax on polished silver..The object is to create a thick enough skin of wax so that it easily peals off. Good luck Darf

Sorry just thought if it fingetnail polish makes an excelent resist. Acetone is the solvent..good luck