Mystery metal left after alluvial Au refine

[Cozza]

Good afternoon all,
So I'm hoping someone can help identify a mystery metal. I was given some alluvial gold to run by a friend yesterday. It was a very dull colour and from an area that is known for its lower purity ( around 90%)
Now I proceeded in deliberately going a non ideal route to refine this lot as I have done gold the correct way and wanted to throw myself a learning curve.
All went exactly as expected.
Method-
-Cleaned, dried and incinerated the 11.27grm of flakes.
- placed in Hcl and heated, then added small amounts of nitric till no reaction occurred.
As expected some silver chloride formed during this process and I was left with a good amount of grey flakes.
I poured off the liquid through the filter and rinsed the silver chloride off the remaining grey flakes and filtered.
I proceeded with the gold drop and ended up with 7.27grm of gold powder and none left in solution according to a stannous test.
Now, I dried the left over grey flakes and proceeded to melt it to get a weight. At first it appeared to be silver with a tiny of copper. 2.78grm in weight.
I have then re melted to make shot as I thought I would digest this in dilute nitric to see if any gold was left behind. To my surprise there was no fizzing reaction with nitric even after 1 hr. It did turn the metal a coppery colour. I added a tiny silver crystal and it fizzled away instantly.

I have photographed the tarnished cornflake to illustrate.
I have then re melted and ended up with a button with a dull gray / purple tinge on top and the bottom is bright silver. It melted within 1min with a mapp torch.

Last photo is after I applied a drop of 68% nitric on the bottom of the button. It left a patch of copper tone and patches of purple but no reaction to the surrounding areas.

I would love some insight on what this might be.
Thank you for your time and consideration

 

[Cozza]

Ok, so now I've had a break and cleared my mind here is my new train of thought.
Upon researching gold from this location, I have found old news articles from the late 1800's on the gold found in the area this lot came from. They mention the miners referring to some being electrum. 60% gold. So if my learnings off the forum are on track, this would mean what i have left here contains too much gold for nitric to penetrate, and too much silver for AR to deal with. Therefore i should inquart what i have left to finish the job.
Am i on the right track?

 

[jimdoc]

Ok, so now I've had a break and cleared my mind here is my new train of thought.
Upon researching gold from this location, I have found old news articles from the late 1800's on the gold found in the area this lot came from. They mention the miners referring to some being electrum. 60% gold. So if my learnings off the forum are on track, this would mean what i have left here contains too much gold for nitric to penetrate, and too much silver for AR to deal with. Therefore i should inquart what i have left to finish the job.
Am i on the right track?

Sounds easy enough to try a test on a small sample.

 

[galenrog]

And that, boys and girls, is why we perform field tests on samples before we start processing larger batches, even on placer gold.

Time for more coffee.

 

[patnor1011]

Next time start with inquarting it first. That way you can process it in one go instead of two.

 

[Cozza]

Well I did say I wanted to throw myself a learning curve :? :lol:

 

[Cozza]

Here are the results
8.12grm twice refined and most of the silver recovered.
Great learning exercise.

 

[glorycloud]

Nice work! Good looking Au and Ag buttons! 8)