Gold leaf?

[fasTTcar]

I have had an offer of a substantial amount of gold leaf, processed in the 1950's.

The client claims to have about 4.5 troy ounces of this material.

Any thing that I should be aware of before trying to buy it?

TIA,
fasTTcar

 

[Anonymous]

Is this 24K or lower, this you should know before paying.

 

[fasTTcar]

It is claimed to be 24k.

I have not tested (or seen it in person) yet. I do not have nitric acid, but I do have some 22k solution and a GT 3000 tester that will give me an indication.

If I work under the assumption that it tests correctly, should I know anything special about this material before sending it to my gold refiner?

Would it be any different that the karat jewelry scrap I normally deal with?

 

[nicknitro]

FasTTCar,

If it is 24K Gold Leaf, why not just offer a reasonable price and process it yourself.

If it is real, I would think you could just melt it. However I would probably dissolve a measured sample in some HCL Clorox, then precipitate the solution till it tested clear of Gold, then compare what I got out to what I put in.

If you plan on purchaseing gold, I strongly recommend you get a full acid test kit, and scratch stone, a file, Hoke's book "Sorry Harold, Should have been first thing.", I have heard of the GT being wrong before. With chemistry, the elements are rarely wrong, just the operator. LOL

How much under spot is your guy asking? If I may be so nosey. :roll:

Good Luck and Welcome,

Nick

 

[fasTTcar]

I have an acid kit, prostone and files as well as a GT 3000 tester.

My plan right now is to drop some 22k solution on it to see how it reacts. If it does not melt, I will offer them a fair price for it.

 

[EDI Refining]

It may weigh 4.5oz now, after melt I could see that weight going down...

I'd buy it on consignment..

 

[goldsilverpro]

The 22K acid will dissolve gold. What will you do then? I think you need something that won't dissolve gold, but will dissolve copper, like nitric acid.

The gold leaf will have rouge on it, which will effectively lower the karat. It would take about 9000 sheets, +/- 20%, of 3-3/8" X 3-3/8" gold leaf to equal 4.5 tr.oz. Are the sheets stacked on top of each other or, is there paper between the sheets? If stacked together, it would be useless for use. The only way I can see it being stacked together would be that someone spent many hours removing the paper. You are better off if it's stacked together since you wouldn't have to deal with the paper. If the sheets are between paper, the paper could weigh as much or more than the gold. Real gold leaf is about .0000035" thick (.09 microns). Fake copper base leaf will be considerably thicker.

 

[fasTTcar]

Thanks Pro, that is the type of info that I am looking for.

I might just take a flyer on it if it looks good and offer $2k.

If I do, I will melt it separately and post my results.

 

[goldsilverpro]

The most common gold leaf is probably 23 karat. The 24K is available but is not used nearly as often. Once you get below about 22K, the color starts to become noticeably lighter.

With the amount of money involved, I would pay to get it assayed in duplicate, at least. Take your own samples (several) and try to make them representative of the entire lot, paper and all. This is not as easy as it sounds.

 

[qst42know]

Is gold leaf too thin for a drop of HCL? Or dilute sulfuric?

 

[nicknitro]

Qst42Know,

How do you mean?
Just wondering, please expand?

Nick

 

[Harold_V]

A wise test for gold leaf is a drop of nitric. If it is not gold, nitric will instantly dissolve the sample, yielding a blue or blue green solution. If it is gold, nothing will happen. Tests with other acids may or may not be conclusive.

Harold

 

[qst42know]

Qst42Know,

How do you mean?
Just wondering, please expand?

Nick

Harold is absolutely right I hadn't given my question enough thought. Though HCL alone would detect brass, HCL and enough oxygen from the air can dissolve thin gold as some have experienced in their AP solutions. I don't believe Sulfuric effects pure gold but may be slow to act on some brass alloys. The use of either of the wrong acids would not provide any answers.

Sorry I asked.

 

[Strider]

wow! I've been away for a while, now i have to catch up.
Cool sheets! Can you use them for some other things not only refining?

 

[Anonymous]

If you did end up purchasing them, you may be able to get more from artists/painters who do leafing/gilding. I do a little myself, but I always use the cheap stuff. Maybe some day when I get better I will purchase real gold leaf.

 

[goldsilverpro]

Actually, that leaf looks quite ragged. It may not be usable. I've used real leaf on my hand carved mahogany signs for 20 years. It's very fragile and it has to be in perfect shape to use it. I can't imagine it withstanding being open to the elements like in the photo. Also, it looks like it's all stacked together, which would make it totally worthless for use as leaf.

 

[boltran]

END RESULT:

ASSAY REVEALEAD THE STACKED - SO CALLED 24K SHEETS" ARE 93% COPPER. UPON EXTENSIVE RESEARCH OF 1950'S ERA MADE FOILS - AND PARTICULARLY WITHOUT TISSUES IN BETWEEN EACH FOIL - THIS WAS COMMON AND UNDER FIVE DOLLARS PER PACK FOUND PRIMARILY IN EUROPE.

ALWAYS TEST OR ASSAY WHAT LOOKS TO BE GOLD - BEFORE YOU BUY IT - NO MATTER WHAT DEAL YOU THINK MIGHT BE IN FRONT OF YOU. FAKE GOLD IS THE MOST REPLICATED SUBSTANCE ON EARTH AND ALWAYS WILL BE.

 

[Topher_osAUrus]

Why are you yelling? :shock:

 

[goldsilverpro]

Real gold leaf is always a solid gold alloy. Fake gold leaf never contains any gold. There's no in-between. The copper alloy fake leaf is always thicker and is usually 5" X 5" square. Real leaf is usually 3-3/8" X 3-3/8 square or various width strips on a spool. Japanese leaf is of different sizes. Real gold leaf is so thin (.0000035") that you can ball a sheet up between your thumb and index finger and it will end up no bigger than a small pinhead. A sheet of balled up fake leaf will be much bigger. And, of course, real gold leaf looks like gold and fake leaf doesn't. You might collect a few flakes on a spot plate, dissolve some with a drop of AR and test with a drop of stannous chloride.

It's not as easy as one would think to refine gold leaf and it's not worth much unless you have a lot of it. There are 2 basic types: that that is stuck to the individual papers (patent leaf) and that that isn't stuck to the paper (loose leaf). You could try to gently burn the patent leaf but it would be hard not to lose gold. You might try to put paper and all into aqua regia but you might have a mess if you aren't careful. The loose leaf can be shaken out of the 25 sheet books but you must not touch it. If you touch it, it will stick to your finger and break up. It will float around everywhere. With loose leaf, I would just shake it into your very dry clean dissolving vessel. cover with HCl and heat, and then feed nitric in drop-wise through an eyedropper. There's only about .375g of alloyed gold in a 25 sheet book. Theoretically. it only requires .36 ml (about 5 drops) of nitric and 1.44 ml of HCl to dissolve 25 sheets of gold leaf. Of course, it will take a lot more HCl than that to cover it.

Maybe one of those oddball gold strippers we've been discussing would work on both types. Just be sure you know how to get the gold out of the stripper.

When I gold-leafed, about half the gold ended up as waste. Unless you're laying leaf on the dome of the state capital or a big flat surface, there's a lot of scrap. Most gold leaf users Artisans usually keep the waste and experience similar numbers. I used several 1000 sheets a year and my waste also contained tape and paint. There's many 1000's of people out there using real gold leaf but, even though I've suggested it, I've neverr seen anyone on the forum take advantage of it. I think It could be obtained for a song.

 

[Topher_osAUrus]

I dont have any gold leaf to process, but Gsp, you have me curious now.

The gold leaf video I watched that was posted by another member showed them putting it between special paper. Would AR be too acidic and break down the paper and(i think it contained) waxes, causing a gel or tough filtering time.?

Would HCl and bleach be a better methodology for putting the thin gold into solution, and possibly not destroying the paper?(which would in turn leave its own issues with rinsing and collecting all auric chloride)- but, I see it would have the advantage of dilution, which would save on acids, and hold the chlorine from the bleach in solution better.

I only ask, because I may soon have the opportunity to refine some gold leaf that is "loose leaf" and filtered waste (the filter from an air system that will be in place while a friend is having the gold leaf redone in his office (in his home), as well as the carpet -which is the same carpet that was in place when it was originally done with gold leaf 50+ years ago)

So two more questions come to mind.;
Would the carpet be a viable source of gold from the flakes and leaf?

And which of the oddball gold strippers would you be mentioning in your post - ecogoldex? Or?

Thanks in advance