Need advice, pointers with gold acid testing (first timer)

[glockngold]

I finally bought some gold testing acid & stones. I want to be able to verify the scrap jewelry I run into & what ever else shows up.

I started with a 10k stamped wedding band & the results seemed to make sense. I scratched 3 traces on the stone. With a drop of 10K acid, nothing seemed to happen. With the 14k acid it slowly disappeared. With 18k acid, the gold trace vanished quickly. So far so good. (right?)

I got similar results with (2) 14k stamped wedding bands. The 10 & 14K acids had no effect.

Now for my screw up & questions...

I bought what I hope is a 1856 $1 gold piece that was holed to be jewelry. (paid $60)
It was hard to get a trace on the stone, but the scratch I was able to make did not seem to react to the 22k acid.

Then (thinking i was sly) looked at that hole in the coin & thought "Lets put some acid right there & see what happens"

It turned to a shiny coppery appearance. And the acid traveled across the surface of the little coin with similar results. (gasp!)

Is my coin a fake? If not, can it be made to not look coppery?

When you do acid testing, what do you use to clean off & neutralize the acid on the stone from one piece to the next?

Thanks.

[Cornelius]

I don't know the answers to your questions, however, I look forward to conversations about this topic. I would like to know about proofing gold. There must be web links about using the equipment you have.

[138]

Part of acid testing with a stone is the "feel" of the metal across the surface. Natural stone for testing is better than the frosted dark glass that is sometimes used. Gold, even 10k, will have a smooth feel with an easy trace and a golden color . Non gold bearing metal will not feel as smooth, the "feel" comes from experience. If you're sure that you laid down a good trace of metal and the 22k test acid didn't react to the trace then the coin should be real. The change in color when the acid traveled across the coin is due to the acid oxidizing the copper content of the 90% gold coin. Unfortunately short of polishing the coin there isn't much you can do restore the color. A little water and a rag is all you need to wash off the stone after testing. Using a base (ammonia, soap, baking soda, etc.) to clean the stone may effect future tests.

[glockngold]

Thanks 138 for the response.
I am new to testing so "having a feel" for things is a way off.
I just got done testing a bunch of wedding bands & almost all of them were easy to scratch a trace across the stone.
The coin seemed harder in feel across the stone. I had thought that since there is more gold in the coin than in the wedding bands, that it would feel softer.


If you're sure that you laid down a good trace of metal and the 22k test acid didn't react to the trace then the coin should be real. The change in color when the acid traveled across the coin is due to the acid oxidizing the copper content of the 90% gold coin. Unfortunately short of polishing the coin there isn't much you can do restore the color.

The coin has little neuismatic value since it was drilled, so I think I'll try a little toothpaste on it.

Do you have any pointers for testing jewelry chain? I always look at the clasps for markings of course, but sometimes I run across broken pieces.
Should I just scratch that across the stone as well?
Or, if I don't care about harming the piece, should I just file into it & just put a drop of acid at the spot where I filed?

[138]

Is the coin magnetic? I've seen fake coins that were plated steel before (both gold and silver). Also, have you weighed it? A real 1856 gold $1 should weigh about 1.67 grams and measure about 15mm across.

For testing chains just rub a good, wide mark on the stone about 1/4" wide trying to rub the same area of the chain on the stone. It's not uncommon to find fake marks on jewelry or even to find legit gold clasps on non gold chains. Real gold chains usually have a soldered connection to the clasp, not just a open jump ring.

[glockngold]

Thanks for those further tips.
I'm away on business the rest of the week, so I'll try that stuff when I return home.

[GoldWampum]

For cleaning the stone I smear a couple of drops of 22k acid on it before rinsing it thoroughly. And yes you will learn the soft peel of gold vs. the harsh scratch of non gold metals.

[glockngold]

Ok, I'm back home.


Is the coin magnetic? I've seen fake coins that were plated steel before (both gold and silver). Also, have you weighed it? A real 1856 gold $1 should weigh about 1.67 grams and measure about 15mm across.

Coin is not magnetic. It weighs 1.6 grams. Remember it has a hole drilled near the edge about 1/8" diameter, so I think that would be in the ballpark. It is about 15mm in diameter.


Unfortunately short of polishing the coin there isn't much you can do restore the color.

Well, that is what I did. It really bothered me to have the 2 different colors copperish & gold. So I used a dab of chrome polish & a rag & the copper tone cleaned off.
I only paid spot for the coin so I am not too worried about issues of cleaning devaluing the piece.


Natural stone for testing is better than the frosted dark glass that is sometimes used.

I imagine I have the el cheapo frosted dark glass you mention. I bought the acid & stone as an ebay package deal.
What confused me in the first place is that it has been easy to get a trace with most of the the 14k wedding bands I've gone through.
I thought since the coin had more gold content, it would be easier to get a trace. (gold being soft)
Perhaps though, the copper in the coin gives more hardness at a 10% amount than the softer silver or other metal that is at a 41% amount.
I also tried to trace on a knife sharpening stone. Using that, the gold coin traced easily. However, when I applied acid, the acid soaked right into the stone even after several drops. The trace was unaffected. So at this point I feel certain the $1. gold is genuine.

Now, How do I know the best stone to buy? One that cuts, but doesn't absorb the acid too quickly?

[138]

I doubt with a hole in it you were about to get the coin graded and slabbed so you're right, a light polishing won't hurt the value. Someone mentioned to me once that due to the pressure involved with the stamping of the coin it hardens the metal a bit so that may account for the harder marking, not sure though.

As for the stone, you should be able to get a good quality natural test stone from ebay also. Try a search for 'natural stone gold test' or 'Arkansas test stone'. I use a small Arkansas stone and it works great for me, a friend that buys and sells scrap PM for a living swears by a big slab of rough cut obsidian salvaged from a rockhounds estate. This stone looks interesting...

http://cgi.ebay.com/3X6-PRO-GOLD-ACID-TESTING-STONE-TEST-SCRAP-/350347540188

May try this one myself!

[glockngold]

Ok, I hope someone can advise me as I continue to try this acid test business.
I just sorted through a box of auction lot jewelry.
I found some sterling stuff, but no marked gold.
I thought i would play around with my acid on some of the probably gold plated chains.
I picked a small chain that i thought just maybe could be a 10K candidate.
I have read online to scratch a spot on the chain to get through the plating.
Then apply acid directly on the chain. (but the tutorial doesn't tell me which acid strength to use.
I took a chainsaw file & roughed up an area on the chain.
Then I laid the chain across the test stone, & put a drop of 10 k acid on it & got no reaction at all.
Next I put 22K acid on the same spot & it bubbled green.
Does that mean the chain could be 10K ??

[GoldWampum]

Sounds like ten or above and less than twenty two. Do you have Fourteen and eighteen acids? Highest clear reading is your value.

[glockngold]

Thanks GoldWampum,
I just tried the same thing with a piece of stamped Italian 14K chain.
As you say the 14K acid has no effect. The 18K acid bubbles green.

[tomexxtra]

Once you get use to using the 14K Acid you can detect 18K, 14K, 10K & sterling silver just by using 14K acid. The streak on the stone will give you a bright gold on 18K. The 14k streak will stay no problem. The 10K streak turns Dark. Sterling sliver will disappear on the stone, but if you file a little mark on the silver jewelry & put 14K acid on it directly it should turn Milky not Green. There is a lot of Sterling on the market that is under .925 % that is marked but it will come up bubbling with the acid. We got so use to the 14K acid we seldom use the other acids while buying Gold & Silver.


Your coin could have been soldered like a tie tack in the center of the coin. They could have removed the tie tack so when you put acid on it, it discolored the solder not really the coin. The coin has no numismatic value, but you should still have the .900 fine gold weight.

The more you use your acid & stone & file, the more confidence you'll have in testing. Also old Gold filled [like old pocket watches]have a heavy layer on it and just scratching is not enough. You have to file into it to make sure it's 14K.
Good Luck with your new venture.

[Rick55]

My husband and I have been married almost three years. We both have wedding bands--I am satisfied with mine. I bought his when we got married and it's pretty big, and he thinks its very comfortable. However, for the last year he's wanted a different ring. He wants one with designs, etc. A year ago, he said he thought he still had his and his ex-wife's wedding set around (10 k gold, $60 for set) and wanted to melt them and some other gold and make another wedding band. I was very hurt, found it distastful and the idea made me uncomfortable. We fought about it, he said finally that he wouldn't do it, that he understood. Today, the subject came up again when we were cleaning a storage room out and found a wedding band. He yelled at me, said I was illogical. I just want to know if I'm the only person that would feel queasy melting and weilding together her husband's previous marriage's bands to go towards a wedding band for their marriage. Thanks, anyone. I'm feeling pretty down

[Mr. Shiny]

Rick55, You may want to direct your question to either of these ladies:

http://1.bp.blogspot.com/_1Ssoxfl0MvQ/RwyvnJNKbBI/AAAAAAAACAI/fBfQGPec-jk/s400/DearAbby2.jpg

[curmudgeonista]

My husband and I have been married almost three years. We both have wedding bands--I am satisfied with mine. I bought his when we got married and it's pretty big, and he thinks its very comfortable. However, for the last year he's wanted a different ring. He wants one with designs, etc. A year ago, he said he thought he still had his and his ex-wife's wedding set around (10 k gold, $60 for set) and wanted to melt them and some other gold and make another wedding band. I was very hurt, found it distastful and the idea made me uncomfortable. We fought about it, he said finally that he wouldn't do it, that he understood. Today, the subject came up again when we were cleaning a storage room out and found a wedding band. He yelled at me, said I was illogical. I just want to know if I'm the only person that would feel queasy melting and weilding together her husband's previous marriage's bands to go towards a wedding band for their marriage. Thanks, anyone. I'm feeling pretty down
Easy solution. Take the offending wedding set to a pawn shop and work out a trade for another band with no personal history attached. That should make you both feel better. He gets his ring. You get to throw out the old wife.

[Mr. Shiny]

Alright, you want the truth, here's the truth.
Wedding bands and chains are mass produced, taking those offense bands to the jeweler won't give you a wedding band with any bad juju attached, he's gonna weigh them, discount the new band by that amount (in dollars), and either polish them up and resell them, or they get tossed in the melt bucket. In spite of what you've been led to believe, jewelers don't take old wedding bands and make new ones from the gold, hell, they barely make anything these days.
You'll feel better about the band that it came from a jeweler, it won't have the taint of the previous love, and it won't have the taint of a pawn shop (sorry Curmudgeonista).

I still think Dear Abby would better serve you.

[Michael.Leclerc]

once you melt the gold and re form it into a new object all of the "old" wife and karma are gone. it's a totally new thing. stop being a whiney over sensitive biiiitch.

[Montecristo]

Not to add further haze to your predicament, but with gold at these prices many jewelers now say they will melt down your sentimental scrap and use it specifically to make a new piece for you, but it has become fairly common for the item to get scrapped and new gold to be used. At first glance this wouldn't seem to make sense as it seems more economical to recycle the customers gold rather than use new, but there is a reason.

The reason is that when a jeweler casts new pieces it's more economical in labor, time and gold to cast several pieces at the same time then to do a series of single piece castings. Each casted piece must be put on a "tree" and then after the casting the item is removed and the "tree" is then used again in the next casting, whenver that may be, assuming it is the correct karat and color. So it's possible that a jeweler will do several different castings and end up with several trees just sitting around that could contain a couple ounces of gold. Also using scrap gold to cast prevents the jeweler from being able to insure a "plumb" 14 karat casting as he cannot be 100% sure of the material used to make the item the customer wishes to recycle and he has even less idea of what solder was used to construct the ring. These unknowns often lead to under-karated and bad castings as sometimes the various alloys in the different scrap items and the solders don't mix well to produce a nice, clean, 14kt plumb, casting.

Now rather than taking a chance with getting a poor casting or an under-karated batch of gold from mixing various forms of scrap and to eliminate the excess gold sitting around of questionable karat and unknown alloys it is easier and yields a better product to tell the customer that he will be re-using your sentimental scrap to make your specific item, but what he really is doing is using new gold and casting several customers items at the same time saving time, labor and money and dramatically increasing his chances of producing a better product on the first try and on subsequent casting when he re-uses the old tree and mixes in fresh gold.

In short, the sentimental wish by the customer to please reuse their gold is often paid lip service, but in reality it is most likely not done.

[Gcubed]

Not to mention how pissed off everyone would be if a hand carved one of a kind wax got wasted on a porous casting due to using "scrap". :s10: