Alloying silver to change its color

[Bill_Kent]

Does anyone know anything about alloying silver to change its color?

We have 750 gold in various colors; could we have 750 silver in yellow or red?

[charlesian2000]

Does anyone know anything about alloying silver to change its
color? We have 750 gold in various colors; could we have 750 silver
in yellow or red?

Sort of. Not really red or yellow.

If you play with the copper content you can get some interesting colour variations. You wont be able to stamp the silver though.

Regards Charles A.

[jhaemer52]

Bill- Yes. It's called Gold and Copper. There are surface treatments you can do but no alloys that I know of.

Have fun and make lots of jewelry.

Jo Haemer
timothywgreen.com

[Ted_Frater]

Does anyone know anything about alloying silver to change its
color? We have 750 gold in various colors; could we have 750 silver
in yellow or red?

Yellow on silver was always a fire gilding process using an amalgam of gold and mercury.

A copper coloured silver can only be obtained by electroplating.

To get any meaningful colour change will debase the silver to the point its not worth the bother.

[alberic]

Hi Bill,

Well, yes, probably. But then you couldn't sell it as silver. Most places have a minimum silver content requirement of no less than 9/10 silver, and a deadly precise requirement of 925/1000 to call it sterling. Depends on the rules wherever you are, but the short answer is, "Yes, but why bother?"

There are Japanese alloys that are down in the 60/40 range with silver, that are a sort of funny pinkish grey. (Shibuichi.) But you normally use those because of their behavior when patinated. If you loaded it up with copper and zinc, you'd just have a very expensive brass.

FWIW,
Brian

[Charles_Allenden]

Hello Bill,

It is possible to alloy silver to get yellow, browns and reds with relatively simple additions of copper and zinc. You have to only think of the different colours of solders (brazing alloys) to realise what is achievable. In Europe the 80% silver grade is hallmarkable and has a pinkish/red tinge to it; as a consequence pieces manufactured in this alloy are usually heavily silver plated. Similarly a 50% silver 50% copper alloy has been used for

commemorative coinage (particularly by the German Mint), however it has its surface depleted of copper to brighten it.

The main issue you will find with these lower silver content alloys is corrosion/tarnish. Unless you use some form of surface lacquer then you will find that the higher copper content silver alloys will discolor or corrode at a faster rate than traditional sterling silver alloys, particularly if you use them in a bi-metal product with regular sterling silver as it will set up an electrochemical cell. Similarly the silver-copper-zinc alloys which would give you the yellows and browns also exhibit a greater rate of corrosion than sterling silver even thought the zinc content of these alloys does give a degree of surface passivation.

There was a US alloy manufacturer that was supplying coloured silver alloys (non-hallmarkable) in grain form and I believe these are still available.

Charles

Charles Allenden

[Bill_Kent]

thank you for your clear and comprehensive responses--greatly appreciated!

bill

[Bill_Kent]

wondering what a 925 silver/75 gold alloy would look like and its workability.

also, 900 silver/100 gold; 800 silver/200 gold.

just curious. thanks

[King_Jamie1]

900 silver/100 gold; 800 silver/200 gold.

One big problem is that you can't legally call these alloys silver or gold in the US because they don't contain enough of either.

[charlesian2000]

One big problem is that you can't legally call these alloys silver
or gold in the US because they don't contain enough of either.

What if you did a 925 silver, but used gold instead of copper? It could be stamped .925 in Australia :-) CIA

[davidphelps7]

Some engravers mix up different alloys to create different colors such as flesh-tone for inlay work. For a few mind-boggling examples, check out Ron Smith's work at the Firearm Engravers Guild of America (FEGA) website.

http://www.ganoksin.com/gnkurl/ep80au

One piece he did was a Winchester 1873 rifle to commemorate the history of the US from the Revolutionary War up until 1873. He inlayed and engraved several different scenes, including a Civil War battle scene, a portrait of Lewis and Clark and another of Lincoln and his son Tad with both the US and the Confederate flags behind them. All of them in full color using various alloys of silver, gold and copper. The flags in the Lincoln portrait are especially striking in that they both have incredibly intricate inlays within inlays; fine silver stars, copper and silver stripes and blued steel to finish.

Experiment, Bill. Mix up different combinations. The metal won't be a total loss if it comes out ugly looking, send it off to be refined and you'll likely get most of the value back. Sure, you might not be able to stamp it with a quality mark, but if your art work is good enough, that won't matter at all. The full color portrait of Sitting Bull on the cylinder of Ron's Colt Dragoon doesn't qualify to be stamped "sterling silver" and "22K". Do you think anybody really cares?

You ought to see Buffalo Bill and Annie Oakley on the other sides of the wheel. You can easily make out the differences in their skin tones (done through the use of more or less gold, silver and copper in each inlay) illustrating the fact that they are all of different races. Sheesh!

Dave Phelps

[King_Jamie1]

What if you did a 925 silver, but used gold instead of copper? It
could be stamped .925 in Australia :-)

Yes, that would be sterling in the US too, but to what end?

[rebecca_rourke1]

750 silver is an archaic french millesimal fineness: mark indicating the 'easterling" contains *.* 7.50% copper and could thus be marked as such ( what we now call sterling or *.* 925 silver (.999 being fine or 'pure silver')..

You could add more copper 80/20 to make reticulation silver or a japanese alloy called shibuichi which is far pinker in colour and shows an array of colours with heat treatment. Other than looking up recipes from ancient texts, you aren't going to get a green silver or blue as you would with gold recipes and common metal additions. You can get yellows (39% and 30% silver respectively) when making bronze and brass materials more like solders for those alloys than malleable metals. rer

[Andrew_Fine]

A few thoughts about this subject:

1) You could get around the hallmarking by saying this is an art object composed of precious metal alloys.

Then in your tag, you could put down a detailed listing for the metal contents in each color used.

2) I understand gold can be alloyed with aluminum to make purple.

I wonder what other colors could be made by alloying silver with metals which are not commonly used, transition elements, or rare earth elements.

Rare earths especially are utilized for coloring glass.

3) I'd be interested to see what everyone else has been able to achieve in alloy mixes. Shibuchi sure sounds interesting.

Andrew Jonathan Fine

[alberic]

Hi Andrew,

Well. not exactly.

1) You could get around the hallmarking by saying this is an art
object composed of precious metal alloys.

Depending on where you are, you can't even say 'precious'. I know the old UK hallmarking rules prevented you from saying anything other than "white metal"or"yellow metal" if it wasn't a hallmarkable quality, or if it wasn't *entirely* hallmarkable. (The early titanium work had trouble with this: might have pure gold on it, but since the Ti wasn't hallmarkable, nothing was.) Don't know how the rules have changed recently. I've heard they've relaxed.

I believe the US rules prevent you from saying 'precious' unless it is of a markable quality. You can say 10% gold if you want to, but you can't say 'precious'. Unless you can pronounce it like Andy Serkus.

2) I understand gold can be alloyed with aluminum to make purple.

Yeah, but it's a really nasty intermetallic. Brittle as hell, and no way to deal with it except to set it like a stone. Look at it cross-eyed and it crumbles.

I recall hearing that somebody'd recently had some luck with a really exotic blue that was half-way stable, but even that wasn't anything like fun to work with.

Regards,
Brian.

[charlesian2000]

Yes, that would be sterling in the US too, but to what end? The end
would be changing the colour of the silver, whilst retaining the
.925 ;-)

I'd never do it mind, although it would be interesting to see the result.

Regards Charles A.

[charlesian2000]

I recall hearing that somebody'd recently had some luck with a
really exotic blue that was half-way stable, but even that wasn't
anything like fun to work with.

I didn't get an exotic blue, but I got a bronze colour with a blue sheen (I keep notes so it's repeatable). The problem is that the melt point is really low, and even soldering with easy solder was risky. Need a lot of heat control. It's also not a carat gold, just an experiment.

Regards Charles A