corrosion: some metals corrode due to oxidation, handling, or exposure to chemicals or moisture.
counterfeit: fake coins or currency that appear legitimate
currency: any kind of money that is legal tender ...
corrosion - A chemical reaction on a coins surface. Corrosion can result from a coin coming in contact with other things such as chemicals and gases in the air. Corrosion can damage a coins surface.
Corrosion
Damage that results when reactive chemicals act upon metal. When toning ceases to be a "protective" coating and instead begins to damage a coin, corrosion is the cause.
Corrosion - Damage which occurs on the surface of some coins, generally due to improper storage. Corrosion is caused when a chemical reaction, such as rust, actually eats into the metal. This is also called pitting in a more advanced state.
CORROSION
Generally any change caused on the metal of a coin by chemical attack which may vary from light surface damage to complete destruction of the coin. The toning seen on many coins is a form of corrosion.
COUNTERFEIT ...
Corrosion - the reaction that takes place on base metal coins caused by the interaction of one substance on another. Corrosion of a coin's surface always results in the loss of metal.
Corrosion is the destructive reaction of a metal with another material, e.g. oxygen, or in an extreme pH environment (either acidic or basic).
The corrosion product is a mix of oxide and salts of the original metal.
Corrosion-effect seen on a coin that has been exposed to the elements. This may be minor, such as toning that is nearly black, to major - a coin found in the ground or water which has severely pitted surfaces.
Corrosion - See "Environmental Damage."
Counterfeit - An imitation of a coin or note made to circulate as if actually money.
Corrosion, such as a pitted surface or toning that is caused by a coined exposed to the elements.
E Pluribus Unum
"Out of many, one"; the motto on many U.S. coins.
Corrosion
Damage resulting from reactive chemicals, often airborne, upon metals.
Counterfeit ...
Copper band corrosion
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On silver coins corrosion can be a problem, but a much bigger problem is crystallization exposed on the surface.
MS70 which removes corrosion and other surface dirt
Rubber Gloves
A soft toothbrush may help with cleaning and removing any dirt that is in the surface of the coin
Baking soda to neutralize the MS70 and soak it in warm water.
Its surfaces exhibit significant wear, from use in ancient times, and severe corrosion, from how the coin has reacted to its environment in being buried for 25 centuries, which combined nearly obliterate the coin's detail.
Also, genuine coins often show some pitting, or porosity, caused by corrosion, though these pits are typically sharper at their edges, wider at their openings, and less round than pits caused by casting.
Some think toning makes a "protective" coating over the surface of a coin that helps the coin resist corrosion. Toning can be even be artifically done by exposing the coin to certain reactive substances.
dimes, quarters, and halves minted presently clash mark(s) Outlines and/or traces of designs from the opposite side of a coin resulting from die clash cleaning any process that removes foreign substances, corrosion or toning, e.g.
Our personal cleaning or restoring techniques of choice for copper and some Zinc cents are to use a good quality silver polish containing an "anti-tarnish" additive or good quality marine metal polish with a corrosion / tarnish protection ...
The flaws shown on this coin were caused by the removal of corrosion or horn silver from the coin. This exfoliated the denser surface layer of the coin and exposed the spongier center.
This is a an original coin showing signs of corrosion (known as pesting) as is common for these tin products. Corrosion has effected part of the edging and has intruded into the legend on both sides.
corrosion-resistant steels) include a broad range of iron-based metals. The name is generic for any steel alloy with a minimum of 11.5 wt% chromium. Common types or grades include 440, 304L, 316L and 904A.
Silver coins are more susceptible to chemical corrosion than gold but even so, it is my view that silver coins should not be cleaned either.
Toning: Toning is corrosion, resulting from surface changes to the metal of a coin at the atomic level caused by corrosive chemical conditions, appearing as a change in color to the coin.
corrosion), then this, too, falls under surface preservation. Any corrosion of metal must be rated on visual impact, similar to a hairline or bagmark.
Ancient coins frequently have dirt and corrosion (patina) products as blemishes. I generally ask two questions when dealing with each coin. Will cleaning be likely to make the coin more readable?
There are some scratches in the reverse fields where corrosion was removed.
T CAESAR VESPASIANVS, laureate head right
/PON MAX TRP COS VI, Victory on large prow left, she holds wreath and palm
Ref.
Condition is close to VG with some corrosion or deposits. The right face of Janus is pretty distinct, but the left is a little hard to see. Obverse is off-center a bit to right, but face is not off the coin.
Copper pieces exposed to dampness will often exhibit oxidation and corrosion. Silver coins are also adversely affected by dampness.
Carbon Spots - Small spots of corrosion, usually seen on copper coins.
oxidation: tarnish or corrosion on a coin caused by chemical reaction with its surroundings. Some tarnish is okay, any corrosion is bad.
P
patina: refers to the surface crust on an ancient coin or the color on a more modern coin.
However, the marketplace allows grading to reflect other factors such as corrosion ("porosity"), toning, nicks and bag marks, etc. If a coin that is technically uncirculated has problems, those problems can be reflected in the market grade and price.
A few very minor corrosion spots are visible on the obverse. The dies were engraved by George H. Lovett, whose initials appear at the bottom of the obverse.
A rigid, transparent, protective casing in which a coin is placed to protect it from corrosion and damage.
Environmental damage
Corrosion-effect seen on a coin that has been exposed to the elements. The damage may range from minor dulling to severe pitting.
Eroded die
Synonym for a worn die.
A true VF coin may be cataloged as only a VG because of a bit of corrosion. It sounds simple, and in practice it works quite well.
Copper is a chemically active metal and, depending on the storage environment, can suffer from carbon spots and corrosion marks. These imperfections must be considered when grading.
spot
A small area of corrosion or foreign substance. Also, short for spot price.
spot price
The market price for immediate delivery of a commodity, such as gold, silver or platinum.
Description of the condition of the coin : Quelques traces de corrosion notamment derrière la tête du roi. De minimes marques de manipulation et de frottement mais le brillant d'origine est largement présent au revers.
Rusted Dies
DIES which have been damaged (pitted) through corrosion. The "rusted" areas of a die create raised bumps on the coin during the STRIKING process thus giving the coin a flat or dull appearance.
...
1799 dollar with heavy corrosion, stains, rim dings, scratches, and a bent planchet. Remarkably, it still sold for $240 on eBay.
Pitted - Having a rough surface due to loss of metal by corrosion
Planchet - The blank metal disk from which a coin is struck ; also called a blank or flan.
Plugged - Denotes that a holed coin has been filled.
Cleaning - Any process that removes foreign substances, corrosion or toning, e.g. application of solvents, dipping, and rubbing with abrasive materials or substances.
Coins with scratches, holes, very dark toning, pitting, corrosion, fake color, retooling, repairs and other problems are severely downgraded.
We think that the PM1 is also the older punch-mark based on the nature of the corrosion products observed at the PM locations.
Here's what our coin looks like after pulling it out. I didn't disturb it while it was "cooking" so you could see better how the corrosion is just peeling off the coin.
It looked pretty horrible before we started.
Next Page ...
William & Mary reverted to issuing copper farthings for circulation in 1694, although about four 1693 dated coins are known with the old tin farthing obverse. The reason for the change back to copper was that corrosion of the tin was becoming ...
The edges are pretty smooth with some cleaning marks and there are some small pits on the surface in a couple of places, but all of this could be results of some spotty corrosion and aggressive conservation.
It is not tooled and the patina is natural. Red is most often an indicator of harmful corrosion but in this case it is very thin red toning or patina on copper similar to that of highly collectible red U.S. pennies.
The steel pennies of 1943 were called silver cents because of their silver grey color. These cents range in color from grey to black because the zinc coating tended to wear off quickly leaving the steel vulnerable to corrosion.
* Heavy or thick patina--obscures the detail of the coin.
* Pitting--Indentations caused by corrosion.
* Scratch--Normally caused by rough handling.
* Scuff marks--Normally caused by circulation and handling.
High humidity or dampness will also result in oxidation or surface corrosion on coins. Silica or silica gel can be used in areas with high humidity when the coins are stored in a safe or lockbox.
*50273 Poland. Litzmannstadt (Lodz Ghetto). 1942. 10 Pfennig (.74) .Type 2, struck in magnesium, with typ corrosion. KM-TN5, C-4751b, F/F Po-572. VG. $100 [image] ...
Most were discovered buried in the ground, causing chemical changes ranging from toning on precious metal coins to patination on bronze coins. Many ancient coins, particularly those buried in acid soil, have suffered from corrosion.
corrosion - chemical reaction on the surface of a coin. counterfeit - a coin or piece of currency that is fake or reproduced in order to make people think it is genuine.
The layout of this obverse is nearest to Breen's obverses 17 and 25, less like 15, 22, and 24, though not identical to any. Even if the "die break" were a creation of whoever tooled the corrosion away, the combination is still a new variety.
The Mint had coated the steel strips before punching leaving the edge of the coin subject to rust and corrosion. Even though a recall was in effect, the Mints own records indicate over 930 million remained in circulation.
 See also: Coin, Silver, Copper, Revers, Mint
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