Info on electrum

Hello everyone,

I would like to get some information on electrum because there doesn’t seem to be much out there. I know it is just gold and silver so it should be very soft, probably only a bit harder than fine silver. What could you make from an alloy this soft? Typically electrum alloys try to mimic the states gold is naturally found in. That is it would be .500 fine, .600 fine, .700 fine or .800 fine, so hallmakring would be a problem, I am guessing hallmark it to the lowest available karat? That is mark the .500 fine alloy as 10K, the .600 fine alloy as 14K etc, or just don’t hallmark it at all (and call it a gold alloy with 60% gold)

Also how is the colour of various alloys versions, I am guessing the .500 fine version would a whitish green, the .600 and .700 fine alloys a stronger green and the .800 alloy a lemon yellow?

I’m talking without knowing a thing about electrum, but alloying metals doesn’t necessarily make them softer. A number of alloys of copper and lead make a quite hard bronze.

I understand that the ancients Greeks valued it very highly.

It should be harder than 24K and fine silver but because it lacks copper it would definitely be softer than most karat golds. Even the 12K version should about as soft as fine silver.

I have made and worked with electrum. It is neither fish nor foul.
30 years ago I had a Woo Woo dude who believed in the magic property of rocks ask me to make him an Electrum mounting for his special stone. He wanted only pure metals next to his stone. So I mixed 1/2 24kt and 1/2 .999 silver together. It was a funky beige color. Not yellow not white. If I recall right it was pretty stiff and worked about like 10 kt gold. The customer loved it.
Just because two metals are soft doesn’t mean that they stay soft and malleable when mixed together. After all you’d think that mixing pure copper and pure gold for red gold would make an alloy like butter. there is an excellent article about red gold and it’s stiffness in MJSA Journal July 2018. In it Shan Athal and James Binnion explain about binary alloys and the difference in the size of the atoms and how they tend to separate.
-Jo Haemer

That’s good to here it’s harder than I thought. Is it green at all, I would like it to strongly green. I will likely use more gold if it’s more a whitish beige.

I’ve made it before as Jo has, using 50/50 fine silver and fine gold. My result was a soft alloy with a faint green cast. Essentially 12k green gold.

If it’s now only “12k” do you stamp it as such or ??. I for one would play it safe and stamp it 12k and have it independently assayed. What is the USA ruling?


Gerry, On my iPhone!

In Canada, don’t we just stamp it ourselves along with a makers mark?

How strong was the green cast? Very faint or relatively strong? Would you compare the hardness to fine silver, copper, sterling?

Just that: a green cast. Faint.

Please excuse any typos-- curse my clumsy digits…

Most often it is the 12K mixture, however if I went with more gold, .600 or .650 I assume the colour would be greener. Would you hallmark .650, with a 15.5K stamp? If I went up to .667 I could hallmark it 16K. I am unsure how to hallmark such obscure karats in Canada, has anyone hall marked more obscure finenesses of gold in Canada (12K, 16K, 20K, 21K) and if so, how did you mark them?