My Silver Love Affair and the Sterling Silver Alloys: Continuum, Argentium, and Sterlium Plus

Sterling silver has always been my favorite metal to wear, collect, and work with. And like many of you, my fingers are crossed for the day it becomes affordable again (if that ever happens). Meanwhile, I get my little joys from finding a $10 sterling silver fork or cup in an antique store that has been languishing there since silver was affordable or finding similar bargains on eBay.

A balled sterling silver headpin on top vs. a balled Argentium sterling silver headpin on the bottom–which would you prefer?

My Sterling Silver Collection

I’ve amassed quite a little collection of sterling silver doodads–bubble wands and bubble wand pendants, a miniature teapot, and candlestick no more than an inch tall each. I have all kinds of pretty little forks and spoons, orphaned salt or pepper shakers, and more. I buy these pretty little things thinking I’ll recycle them into silver jewelry . . . but I get too attached to them and just keep them like they are. (Hoarders: Sterling Silver episode?)

So I’m back to having to buy sheet silver if I’m going to make jewelry out of it. And while silver shopping, I’ve discovered that I’m such a metal geek. I’ve always known I was a gem geek, but in the past year or two I’ve really noticed that I geek out on learning about all kinds of metals, too. Especially ones used for jewelry making and most especially sterling silver and its fancy new alloy cousins. I had the pleasure of being invited to attend Stuller’s Bench Jeweler Workshop a couple of weeks ago. During the workshop I sat in on lectures about casting, refining metals, sterling silver alloys, and more. I was in geek girl heaven, and my favorite part was learning more about sterling silver alloys.

Sterling Silver Alloys

Marie Scarpa award winning design, argentium silver, sterling silver alloy
This Argentium design by Marie Scarpa won first prize in the 2009 Jewelry Arts Awards.

Imagine never having to scrub fire scale from your silver jewelry creations, drawing balled head pins that are as shiny as the wire was when you started. Fusing sterling silver without solder, setting high-end stones in sterling silver without worrying about prong strength. Not having to worry about tarnish, casting sterling silver jewelry that’s as hard as 14K gold jewelry. These are possibilities with the sterling silver alloys Argentium, Sterlium® Plus, and ContinuumTM, along with a bright whiteness that rivals platinum for a fraction of the cost. They cost a little more than regular sterling silver, but for the right project, the added cost is worth it in the time you’ll save. Here are just a few enticing details about each of these alloys.

Argentium Sterling Silver

Argentium sterling silver has roughly the same composition as sterling silver, composed of 92.5% pure silver, but instead of sterling’s 7.5% copper content, Argentium sterling silver has germanium smelted into that copper. That makes Argentium sterling silver react to the torch differently. Regular sterling silver reticulates (wrinkles) and forms a lumpy appearance when balled, whereas Argentium sterling silver melts or balls into a smooth, shiny teardrop. And instead of fire scale that forms on regular sterling because of the copper content, Argentium sterling’s germanium reacts with oxygen to create germanium oxide on the surface, which is bright, shiny, and attractive. The germanium content in Argentium sterling silver also makes it tarnish resistant and bright white much longer than regular sterling silver.  

Annabel Alleyne shared her Argentium filigree earrings, sterling silver alloy
JMD member Annabel Alleyne shared her Argentium filigree earrings in our gallery.

Argentium’s fusing capabilities paired with its strength make it ideal for filigree. Argentium solder exists and you can also use regular silver solder (hard solder is not recommended). You should wait a moment before quenching Argentium sterling after heating, and don’t pick up with tweezers, use a third hand, or otherwise assert pressure on Argentium when it’s hot as it can shatter. Much like clay in an oven or glass creations are “cured” in a kiln, it’s recommended that Argentium pieces are hardened before use. You can harden them by “baking” in an oven set on 500-525° F for about 90 minutes (or in a kiln for about an hour at 575-580°F).

Update: Here’s a very thorough article from Rio Grande about working with Argentium sterling silver.

Sterlium® Plus Sterling Silver

Another sterling silver alloy that has superior tarnish resistance is Sterlium® Plus sterling silver, which also gets its user-friendly qualities and bright whiteness from the addition of germanium and requires no rhodium plating to maintain its brightness. Sterlium® Plus is ideal for casting and use with a rolling mill, and it’s more malleable and ductile than traditional sterling silver. Sterlium® Plus is virtually free of fire scale, can be fused without solder (like fine silver, but regular silver solder will work on Sterlium® Plus too), and can be balled with a torch.

Howardlb freeform pendant cast in Sterlium sterling silver, sterling silver alloy
Also in the JMD gallery, member Howardlb shared this freeform pendant that he cast in Sterlium sterling silver. See his earrings cast in Sterlium silver and molds made from old spoon handles here.

Sterlium® Plus is not suitable for making mokume gane, and Sterlium® Plus sheet will not reticulate (wrinkle) under the flame like sterling silver, ContinuumTM sterling, or 80/20 reticulation silver will do. Sterlium® Plus is harder than standard sterling silver, allowing for more secure prong-setting of gemstones. Sterlium® Plus silver jewelry should be hardened at 600°F for about an hour.

ContinuumTM Sterling Silver

ContinuumTM is a sterling silver alloy that Stuller developed. It’s over 95% precious metal and contains no nickel. It allows you to get the look but also some properties of 14K white gold or platinum at a fraction of the cost, because of its resistance to tarnish and oxidation as well as its hardness–the hardest sterling silver in the industry, which allows for the safe, worry-free setting of even higher-end stones in silver jewelry. But even after hardening, ContinuumTM sterling silver remains ductile and retains springiness.

ContinuumTM can be enameled, fused without solder (just like fine silver fuses to itself), and cast much the same way sterling silver is cast. ContinuumTM wire balls up nicely in a torch and, unlike Sterlium® Plus, ContiuumTM sheet can be reticulated. The hardening process for ContinuumTM is two-part process and a bit more involved than for Argentium or Sterlium® Plus.

To learn more about working with sterling silver, sterling silver alloys, and how to make artisan-quality silver jewelry, trust the expert jewelry artists featured in Lapidary Journal Jewelry Artist magazine. You can keep an entire year’s worth (nine issues!) of Lapidary Journal Jewelry Artist on hand in a clutter-free format with the 2011 LJJA collection CD or instant digital download.


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