dipped silver coins

Does anyone know if there is a way to chemically test a silver coin to discover if it's been dipped? Like the police forensic tests that are done which show blood traces even after an attempted clean up.
thanks kes

 

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The acidic solvent in most dips is Thiourea.
Properly dipped coins always have any residue of this chemical neutralized and rinsed away.
I wouldn't doubt that a scientist would be able to test for it anyway, but I have never heard of this happening.

 

Another thought. Why would you want to add another chemical to your coins? The solvent in dips are harmful enough, and always leaves a telltale sign if you know what to look for. Adding other chemicals to test for dipping would also leave their mark on the coin.

 

Hey, what a great idea! Let's get a chemist to invent a solution you could dip your coins in to see if they've been dipped........no, wait a minute here.

That would mean that even if your coin passed the test, it would have been dipped in chemicals anyway.

Seriously, I buy dipped coins all the time. When they're good examples of a year/mint, some customers don't care that they were dipped. I always tell potential buyers that they're looking at a cleaned coin, but not everyone worries as much about it as some do.

Dipped coppers always look bad to me. Dipped silver or gold usually looks good despite the loss of luster, but dipped cupronickel is a ruined coin in my book.

 

Cute cmbdii , but I admit it, I laughed!! However, I thing you missed a little detail. Forensics specialists use lights! I was thinking more along the lines of a light with a specific wave length. That's how Forensics specialists find blood residue on objects even if it’s been washed with bleach, gun powder residue same thing you can wash you hands but it still shows up under a specific type of light.

I don't Dip and do the same as you do. I can't imagine why any one would dip gold! I could see a little ivory soap and water, but that's about it. FYI gold will dissolve in bleach. I heard of a woman who decided to soak her engagement ring in bleach over night. When she checked it in the morning the ring was gone! So, in disgust, she threw the bleach in the toilet. The only problem was that bleach doesn't dissolve diamonds. One and a half carats down the tubes!

 

Not if she was using aqua regia* as a bleach

*aqua regia or aqua regis: literally "water of the king", a mixture of concentrated nitric and hydrochloric acids capable of dissolving the "royal metal" gold. [Glossary of archaic chemical terms at http://webserver.lemoyne.edu/faculty/giunta/archema.html]

 

Hi CyberPunk,

It seems that Luminol is a chemical that is applied to surfaces that are suspected to have been contaminated with blood.
The Luminol reacts with blood, and produces a compound that is visable under UV light.

LUMINOL

 

thank's Jody526 that's what I was asking about. It seems there is no non-distructive way to test. I see WAY too many 40-47 walkers that are just too "Blast Whites!" that sell for under $15 and if they were real they would be worth much more. I've seen some NGC slabs, not that their perfect, with a note under the grade saying "Chemicaly altered". So I wonder if it's a judgement call on their part. Currently I use 20/20 and if it looks too good to be true it probably is. It's just that some Walkers could be MS66+, but again there are way too many.

 

Well I have met many graders over the years, and none have been perfect. They in all honesty are doing a tough job with their best efforts. Some of the major grading firms make the new graders work many hours honing their skills. They learn to pick out forgeries and altered coins. It takes a lot of practice to learn grading. This is a job I would not take for hundred times the money they earn.
Now as most of you are aware, the major grading services guarantee their grades and authenticity. How would you like to be the grader of that coin. Those bar codes give a lot more info than most realize.
Each firm will know the graders who certified the coins.
It is a tough job, and my hat is off to them that do it.

 

Yeah, CyberPunk, I know exactly what you're talking about.
Do you know what "flow lines" are? They are lines, on the surface of coins, that are the result of metal being pushed into the recesses of a die during the striking process.
These metal flow lines are visible under strong magnification.
A coin that has been overly dipped, will have these flow lines obscured or, for lack of a better word, melted away.
It can take a long time to learn to recognize suptle differences in coins like this, but this forum is a great place to reduce the learning curve.

 

Hi GDJMSP,
Modern refined chemicals, compounds, and inventions often have a bit more “punch” than their ancient counterparts. The 2000 year old Babylonian Battery works and I would give me a little shock (maybe), but that doesn’t mean its ok to stick my finger in a light socket.

I know from my chemistry classes that gold is considered an incorruptible metal, but sulfuric acid will dissolve it and it can not be recovered. Regina Purgandum Vestia, can be paraphrased as ‘Queen of the Laundry”, is a mix of chlorine, sodium hydroxide (a base) and water. My info came from a jewelry maker not a metallurgist so you may be correct. I would like to know if what you are saying is true. So, I propose a test. Would you be willing to drop that gold coin of yours in a cup of undiluted Clorox for a week or two and if it remains unchanged I’ll buy it.

 

I have some gold flakes. I will put one in a solution of clorox to test the theory. This way we aren't ruining gold coins. I will post the results in one week.

 

Hi National dealer and satootoko
I don't seriously propose we drop a coin in it's just me being a smart ***. I do grading myself and have spent years of Friday nights till dawn trying to hone my skill before I started to grade. Yah, grading is a not an easy thing esp. the G-EF range that's where most of the mistakes are made and normally on the high side. I've down graded a lot of VF-20's to F-12's or even G-4's. Even so, I do the garentee thing also, and I've made some mistakes, too many!

Anyhow, here's one for you that’s not a Urban Legend. I saw an 1879-CC Morgan rated MS-60 and slabbed by NGC. At the bottom of the container was one of the C’s. It fell off.

 

Well I have seen many altered dates over the years. Many added mint marks, and even numbers in the dates. The ANA had a few of these types of coins on display at their convention a few years back in Atlanta. One coin had a five digit date. It was a site to see. It just goes to show you how important knowledge is.

 

My gold flake has been sitting in clorox overnight, and it is still there. No difference yet. Well, maybe a little cleaner.

 

I've been reading a little about the reaction bleach has on gold.
The best I can tell, it (chlorine bleach) won't react with "pure" gold.
Chlorine will, however, disolve copper and nickel, and will also destroy gold alloy, or karat gold (10k, 14k etc.).

GOLD REACTION

 

Well, I hope it turns out ok, but I think you need to take things a little less seriously. You saw my other postings on this topic; personally I’d don’t even put ANY coins in ANTTHING, not even water.
Well, good luck and if I’m wrong I’m wrong, end of story.