Cleaned Coins

gawd0wns,

We're not ignoring you. This is a very tough subject to answer quickily. I am not at a place where I can access the photos I need for examples. Hang in there and I'll get back to this with examples.

Caveat ... I only have U.S. examples. Others may have some Canadian examples to share.

Small lines going the same direction is a good sign of cleaning, so are dirt hidden in the devices. Cleaned coins also lose their luster.
Harder to spot coins that have been dipped but they are unusually bright and flashy.

If you go into my gallery (below my sig), the following coins were noted as cleaned by ANACS.

1856 Flying Eagle cent
1877 Indian Head cent
1909-S VBD Lincoln Cent
1856 Seated half dollar

"Another process that is used to clean coins, both copper and silver is called whizzing. Whizzing is a process that uses high pressure water and a brush in a swirling motion to clean the coin. Coins that have been cleaned using this process are easily detected with a 10x magnifying glass. The tiny scratches are usually not seen with the naked eye, however, when looking under a 10x glass the scratches are easily detected. No coins are going to endure hundreds of fine scratches in a swirling arrangement.

"Silver coins that have been cleaned are usually dull and sometimes the toning is left around the finer details of the coin. For example, look out for older silver coins that have a flat dull looking surface with blackish color around the small stars or other details in the coin. These coins are most likely cleaned.

"There is a process of cleaning silver coins that is called dipping. Dipping is generally accepted between collectors, since the only effect is the removal of surface yellowing or browning on uncirculated coins. The dipping solution was invented by a chemist that developed the process. Even so, a reside is left on the surface of the coin and it can be detected by major encapsulation services."

(This is directly quoted from smccoins ebay page.)



"If the coin has been cleaned with an abrasive, the coin will have hairlines. Also, abrasive cleaning often leaves some crud in the recesses of the coin (untouched dirt or left over abrasive).

"If the coin has been dipped, it may or may not be detectable. A bright white 1801 half dollar is immediately suspect. Although it is possible for such an original coin to exist, it is unlikely. Also dipping can strip the lustre off of the coin, with the end result that there is no lustre where you would expect it to be for a coin in said condition (XF and better coins).

"Copper/bronze/brass coins that have been cleaned have an unnatural color, often looking like a toned gold coin. Even after they re-tone, they tend it tends to be uneven and a slightly odd color (watch out for dark areas).

"Exactly the other way around, silver coins that have been cleaned tend to be extremely uniform in color after they re-tone, including the tops of the letters and protected areas. Silver coins with natural toning will usually show some variation in the color at these places. Be aware that a uniform slate gray color can be produced on silver very easily with a number of chemicals. Finally, a heavily toned and subsequently dipped silver coin will tend to have a gray appearance caused by surface roughness rather than tarnish. This can be detected by careful examination with a strong magnifier.

"The ANA advises that sudden "hard line" changes in color do not occur on naturally toned coins. Naturally toned coins exhibit a gradual change in color or darkness."

(This is directly quoted from Telesphere Numismatics web site.)



"Magnification is the best way to differentiate weakly struck coins from worn-die and lightly whizzed coins. On weakly struck coins, flow lines will still be present and luster will still "cartwheel." Worn-die coins may not have much "cartwheel" but still may have radial flow lines often the result of die erosion. Whizzed coins will appear smooth, and because the flow lines have been disturbed, they will not have normal "cartwheel" luster, but rather a diffused look.

"In yet another form of surface alteration, the surfaces of Proof coins are heated to actually melt the hairlines or other defects. This method may involve anything from a match held under the surface for a few seconds to a high temperature torch selectively applied to a specific area. Coins altered in this manner sometimes have a wavy look or different "depth" to the mirrored surface. These clues are especially noticeable on Proof gold coins, since the surfaces are so delicate. Also, many Proof gold coins have "orange-peel" surfaces that are flattened by this method. If the mirrored fields vary across the surface of a coin, heat treatment of the fields is often the cause.

(This is directly quoted from the PCGS web site.)

We should probably discuss circulated coins and uncirculated coins separately since the diagnostics are very different.

For circulated coins, use everyday examples as templates. A common, uncleaned circulating coin will display even wear starting at the high points of the design. It will acquire coloration (staining or toning) uniformly on the surface, but this may be rubbed off on the highest points if the coin circulated after toning was acquired.

Cleaned circulating coins may display surface scratches or abrasions from contact with a wire brush, rubbing with a cloth or other cleaning tool. These scratches are normally most evident in the fields and are uniformly in the same direction. Magnification may be needed to see them, but on harshly cleaned coins the naked eye can pick this up.

Another diagnostic is residue (dirt or toning) in the recesses of the design with clean fields on the rest of the coin. Normal abrasive techniques can't reach the recesses, so that material remains. Here's an example that shows both scratches and residue left in the recesses:




A uniform color (either dull or shiny) may also indicate a previous cleaning. If the coin looks different from other normal circulating examples, be suspicious. Here's an example:




Note the uniform color on this 87-yr-old coin. You can see wear on the high points of the design that indicate circulation, yet it displays no coloration or toning anywhere on the coin. This coin show some toning.

For uncirculated coins, the biggest problem is "dipping". If an uncirculated coin acquires toning, some coin collectors can't stand it when their prize doesn't look like it just came from the press. The minting process leaves the newly stamped planchet with "mint luster" caused by the high pressure and metal flowing into the recesses of the die. It creates a cartwheel effect that can be viewed by holding the coin where light reflects toward your eye and rotating the coin. It will appear like windmill blades or cartwheel spokes. Coin dips use a form of acid that removes sulfur oxides from metal surfaces (toning) and some of the original metal, too. If dipped numerous times, the surface luster and cartwheel effect are lost. This is very hard to see from a photo and single dips may be undetectable. But ask yourself ... will a 100-yr-old uncirculated coin look the same today as it did in 1908. Unless it was stored in the correct environment (uncontaminated and airtight), the answer is "no". All will acquire some color. Pure white examples of silver coins probably have had some help. Bright red coppers even more so. Finding high-mint-state examples with untouched surfaces is very hard to do.

Thanks for listening ... I'll post more examples as this post progresses.