How can you tell if a coin has been dipped/cleaned and has retoned?

MidLifeCrisis · February 13, 2011 11:20AM

Or, put another way...what do you look for as an indicator of originality?

lkenefic · February 13, 2011 11:26AM

If the coin is 150+ year old silver, the chances are slim to none of it being "blast white", especially if it's a lower demonination that would have seen quite a bit of use in commerse, but I suppose there might be a few very high grade exceptions. I guess it depends upon how harsh the dip was initially and how long ago it was as to whether or not the coin will retrieve its original skin. The tip-off for me is a mostly white center with wild peripheral toning.

Goldbully · February 13, 2011 11:28AM

<< Or, put another way...what do you look for as an indicator of originality? >>

Great question....I dunno!!!

llafoe · February 13, 2011 11:32AM

I suspect the answer is experience and a lot of coins passing through ones hands...

shottaker · February 13, 2011 11:34AM

Many bag coins (morgans, some peace, some walkers) usually werent dipped and a surprising number in original bags are still blast white even today. That said a huge number were dipped for a small toning spot here and there. Oftentimes the color they show when retoned isnt the same as original toned pieces. Spotty brown (dip residue that was left on the coin) is easiest. Its streaky and not pretty at all. Yucky yellow is a sign of overdipping and is a chicken broth type color and is permanant and will never change even with more applications of dip/
Many will have just a slight rainbow from being in an album. These coins are very difficult to tell from original white coins placed in an album and left a few years.
Honestly ask a few guys who have decent coin eyes and/or if it looks nice to you buy it and enjoy it.
The reason that dipped coins get holdered is that if done correctly it does not perceptibly change the coin or its long term health. Thats the party line and if you want to read between the lines "if done well we cant tell, and neither can dealers".

The right color combo helps in trying to tell if its original but its subjective and not 100% (anyone that says they have those kind of xray eyes are full o bs). Takes a long time. Taking a look at holdered older type coins and the colors they have is a good indicator of the stuff thats at least acceptable as original. On occasion some stinkers are holdered but most are a good training tool.

TomB · February 13, 2011 11:35AM

I generally use my numismatic experience and a heaping of my research scientist experience.

coinguy1 · February 13, 2011 11:43AM

Among other things, I look for:

Surfaces which are lighter then one should reasonably expect for a coin of that era.

Toning which appears to be of the type found on older coins that have been dipped and which later re-tone. For example, coins that are mostly white, with vividly toned peripheries.

Evidence of a dipping, such as light stains that don't match other areas of the surfaces, white splotchy areas, dip residue, toning remnants in protected areas of an otherwise color-free coin, or other signs that toning has been removed.

Obviously, generally speaking, the older the coin type, the more likely it is that a color-free one has been dipped. For example, there are plenty of white non-dipped Washington Quarters. And a much smaller number of Standing Liberty Quarters. And some, though considerably fewer, still, Barber Quarters. When it comes to Seated Quarters, the odds are incredibly slim, and for Bust Quarters, I doubt that there are any. And so on.

Edited to add: In many instances there is no way to KNOW and all you can do is make an educated guess.

MidLifeCrisis · February 13, 2011 11:43AM

<< I suspect the answer is experience and a lot of coins passing through ones hands... >>

Well, that would be how you get better at it...but what criteria would you use to decide if a coin is original? What attributes should a collector look for?

lkenefic's answer (a mostly white center with wild peripheral toning) seems reasonable.

There are certain things I look for. For example, in my opinion, color and surface quality can be good indicators of originality. In copper, I prefer a smooth, hard planchet with a nice, even warm color that reminds me of milk chocolate. For silver, I look for the same attributes in the planchet and natural but subtle toning that comes with age. On all coins, I look for dirt and other gunk between the devices.

But what do you think?

Edited to add that I appreciate the other comments that were posted while I was drafting this post.

Sonorandesertrat · February 13, 2011 1:19PM

MLC,
Good post. Some of my thoughts:
1. Even color is not always a good thing to see on a coin. For example, if the color of an early copper is too even (especially if both sides have the same look), I might wonder if it had been recolored. Sometimes hints of an old cleaning of an early copper, and subsequent recoloring or retoning, can be seen as tiny bronze-colored (or pink) patches in recessed areas. Many brown early coppers and spotless red coppers were recolored at one time, especially mint-state coins.
2. Look for luster, or lack thereof, on mint-state coins. Repeated dipping will attenuate the luster on a coin---there is an old article (by Anthony Swiatek, as I recall) that clearly showed this. I remember seeing an 1893S Morgan dollar in a PCGS MS60 slab, despite the fact that it was mark-free and had no wear. The strike was quite weak, and the luster was completely nonexistent (the coin had a dull, gray color).
3. Do the fields look clean, while some recessed areas and/or regions around design elements (e.g., stars, an eagle, Miss Liberty) look notably darker, like dirty halos? If so, I would conclude that it had been lightly cleaned and retoned (i.e., the person who cleaned the coin didn't finish the job before the toning process started anew).
4. Sometimes the toning is so dark and impacted in places that a kind of 'tone-burn' has set in---this won't always dip off (no matter how repeated the dipping is). Coins with dull, mottled, off-white, faint gray, and faint beige surfaces got that way with help.
5. If the coin has marks, such as scratches, look at them carefully. Do the scratches have a slightly different patination? If meaningful scratches are on a cameoed design element, they should not themselves be cameoed (this would indicate doctoring).
6. Occasionally, small mint-made grease stains are seen (especially on gold)---an indicator of originality.
7. I view silver coins with brilliant white centers and colorful edges as having been dipped and retoned (or even AT'd).
8. Look carefully for evidence of fluid flow (especially chemical seep from a design element to the adjacent field) that would indicate that a chemical was applied to the surface to induce toning or frosting.
9. Look at both sides of a coin. Does one side have unappealing, patchy toning that is quite dark in places, while the other looks clean, lighter overall, and much more uniform in color?
10. Coins with any toning need to be examined with special care. Sometimes there are hairlines underneath the toning, indicative of an old cleaning.

AMRC · February 13, 2011 1:41PM

<< I generally use my numismatic experience and a heaping of my research scientist experience. >>

What Tom said, but without the "research scientist" part.

ebaybuyer · February 13, 2011 1:54PM

interesting question, if coins could talk they could tell us what a previous owner has done, they cannot so our best conclusion is an educated guess.

Barberian · February 13, 2011 4:45PM

<< I generally use my numismatic experience and a heaping of my research scientist experience. >>

How does your experience as a research scientist help you, TomB? My experience as a research scientist has apparently resulted in my selecting and purchasing a whole lot of problem coins (off EBay). I find that out when I use my lab microscopes to inspect my purchases.

Frankly, I need to considerably improve my numismatic experience and know-how. I'm slowly getting better, though.

GoldenEyeNumismatics · February 13, 2011 6:41PM

<< 

<< I generally use my numismatic experience and a heaping of my research scientist experience. >>

How does your experience as a research scientist help you, TomB? My experience as a research scientist has apparently resulted in my selecting and purchasing a whole lot of problem coins (off EBay). I find that out when I use my lab microscopes to inspect my purchases.

Frankly, I need to considerably improve my numismatic experience and know-how. I'm slowly getting better, though. >>

Generally speaking, I advise against using a lab or observation microscope to view coins. Stick to a low powered loupe.

Frankcoins · February 13, 2011 7:20PM

Honestly, often you can't.

Barberian · February 13, 2011 8:37PM

<< 

<< 

<< I generally use my numismatic experience and a heaping of my research scientist experience. >>

How does your experience as a research scientist help you, TomB? My experience as a research scientist has apparently resulted in my selecting and purchasing a whole lot of problem coins (off EBay). I find that out when I use my lab microscopes to inspect my purchases.

Frankly, I need to considerably improve my numismatic experience and know-how. I'm slowly getting better, though. >>

Generally speaking, I advise against using a lab or observation microscope to view coins. Stick to a low powered loupe. >>

Usually I do at shows or shops, but I would receive EBay-purchased coins where I worked and would check them out using a dissecting scope at 7X. I think I understand your point, i.e., keep the magnification lower (2-5X), but the clarity and resolution at 7X with a single fiber optic light enables quick recognition of hairlines vs die polish lines. Of course, it's great for attributing varieties, too.

Sonorandesertrat · February 13, 2011 11:03PM

Doug Winter has a commentary on his website (www.raregoldcoins.com) concerning rare gold coins and original-looking toning (with color pics)---it is worthwhile reading and relevant to this topic.

ricko · February 13, 2011 11:15PM

Experience, with a generous dose of metallurgical knowledge (such as TomB) is your best hope for identifying such coins. As Frank said though, it is not always possible. You may be able to screen out the amateur efforts, and even some of the better ones. We will all miss the really good ones. Cheers, RickO

Juan · February 13, 2011 11:36PM

I picked up a Walking Liberty Half a few months back and it was so shiny an dclean that it reminded me of my half-bro in childhood who took some liquid mercury and rubbed it on a silver coin and boy it sparkled. I can't say anything bad about him because it wouldnt be right but as Moms Mabley used to say, ...

Sonorandesertrat · February 14, 2011 12:19AM

<< Experience, with a generous dose of metallurgical knowledge (such as TomB) is your best hope for identifying such coins. As Frank said though, it is not always possible. You may be able to screen out the amateur efforts, and even some of the better ones. We will all miss the really good ones. Cheers, RickO >>

partagas · February 14, 2011 5:18AM

Classic case of cleaned retoned garbage

http://cgi.ebay.com/1844-Seated-Liberty-Quarter-CHOICE-AU-/290534415832?pt=Coins_US_Individual&hash=item43a5335dd8#ht_3742wt_1139 cleaned retoned garbage

fastfreddie · February 14, 2011 5:56AM

<< Classic case of cleaned retoned garbage

http://cgi.ebay.com/1844-Seated-Liberty-Quarter-CHOICE-AU-/290534415832?pt=Coins_US_Individual&hash=item43a5335dd8#ht_3742wt_1139 cleaned retoned garbage >>

And yet the shil bids continue. What gives?

OKbustchaser · February 14, 2011 7:20AM

<< How can you tell if a coin has been dipped/cleaned and has retoned? >>

If properly dipped then the first couple of times it's done, you can't. Even those who claim differently can only make an informed guess. Thus my classification of "original now".

coinguy1 · February 14, 2011 8:34AM

<< 

<< How can you tell if a coin has been dipped/cleaned and has retoned? >>

If properly dipped then the first couple of times it's done, you can't. Even those who claim differently can only make an informed guess. Thus my classification of "original now". >>

Depending upon the toning that was on the coin, that's not necessarily true. You can dip a coin "properly", but still leave evidence (remnants of the toning) that it has been dipped.

roadrunner · February 14, 2011 8:52AM

How can you tell if a coin has been dipped/cleaned and has retoned?

Often times I can tell just by who the person is claiming the coin is all original.

There are a number of all white 1857-1858 and 1879-1890 seated quarters which I would think are probably 100% original. I saw a 90% white and blazing frost on frost PCGS MS64 bust half 2 yrs ago that the owner claimed was fully original. Other than for a slight Morgan-dollar like crescent along the edge the coin was as close to pure white as could be expected. The luster did not change in texture or depth from edge to edge or side to side. Seeing frost on high points I had never seen before lead me to believe it was very possibly an orig 90%+ white coin....nearly as bright as original bag-sourced Morgans.

roadrunner

Bayard1908 · February 14, 2011 11:32AM

<< How can you tell if a coin has been dipped/cleaned and has retoned?

Often times I can tell just by who the person is claiming the coin is all original.

There are a number of all white 1857-1858 and 1879-1890 seated quarters which I would think are probably 100% original. I saw a 90% white and blazing frost on frost PCGS MS64 bust half 2 yrs ago that the owner claimed was fully original. Other than for a slight Morgan-dollar like crescent along the edge the coin was as close to pure white as could be expected. The luster did not change in texture or depth from edge to edge or side to side. Seeing frost on high points I had never seen before lead me to believe it was very possibly an orig 90%+ white coin....nearly as bright as original bag-sourced Morgans.

roadrunner >>

I've owned a couple of white 1879 quarters. I was suspicious of one but think the other was original.

Unknown · February 14, 2011 12:00PM

This content has been removed.

Prethen · February 14, 2011 11:07PM

This thread gets a big thumbs up from me! Great discussion.

MidLifeCrisis · February 15, 2011 8:34AM

<< This thread gets a big thumbs up from me! Great discussion.

>>

Thanks. I'm surprised the question hasn't been asked more often on the forum.

(Then again, maybe it has...I didn't do a search.)

pakasmom · February 15, 2011 9:18AM

<< [Rolled coins, (silver) even if "blast white", should have slight to moderate patina between/on the reeding.

<< 

Valuable tip.

Good discussion...

JRocco · February 15, 2011 10:43AM

<< 

<< This thread gets a big thumbs up from me! Great discussion.

>>

Thanks. I'm surprised the question hasn't been asked more often on the forum.

(Then again, maybe it has...I didn't do a search.) >>

This is a great discussion that should be aired every so often.
I learn a little more every time too.

ColonelJessup · February 16, 2011 7:28AM

<< How can you tell if a coin has been dipped/cleaned and has retoned?

Often times I can tell just by who the person is claiming the coin is all original.

There are a number of all white 1857-1858 and 1879-1890 seated quarters which I would think are probably 100% original. I saw a 90% white and blazing frost on frost PCGS MS64 bust half 2 yrs ago that the owner claimed was fully original. Other than for a slight Morgan-dollar like crescent along the edge the coin was as close to pure white as could be expected. The luster did not change in texture or depth from edge to edge or side to side. Seeing frost on high points I had never seen before lead me to believe it was very possibly an orig 90%+ white coin....nearly as bright as original bag-sourced Morgans.

roadrunner >>

There was a multiple-roll group of 1877 25c quite a while ago. Blast-white and 65 was low end.

How can you tell if a coin has been dipped/cleaned and has retoned?

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