Do you agree or disagree with this statement and either way, please explain why?:Toning is corrosion

coinguy1

Thanks.

michael

well i do not agree

it all depends

now as for coins that have below average eye appeal , the toning is ugly, too dark, and way too thick, or has eaten into the subsurface of the coin then i do not like it at all and THEN i consider it corrosion

if the coin has for me
great eye appeal
toning that sits properly on the coin and does not eat/is actively eating into the surface of the coin
and is not dark or hurts the coins eye appeal
and the toning does not obscure the mirrors or lustre
and the toning is not fugly or with residue and is natural and just sits on the coin not eaten into it even if the coin has a thick really thick crusty original skin


then i consider it patina and this is all well and good for me

Longacre

I think it is, by definition, corrosion. Maybe some of the chemical engineers in the house can explain the technical reasons behind it and why it may or may not be corrosion by definition.

LanLord

Isn't corrosion a chemica or electo-chemical reaction between a material (usually metal) and it's environment which usually produces a deterioration of the metal and it's properties?

If so, I'm not sure I agree that toning is causing a deterioration in the metal and it's properties.

MadMarty

If it wasn't for toning, the dip manufactures would go out of business.

TwoSides2aCoin

Toning has a tremendous effect on metal, but it is not corrosive. It is more adherence to another property. I don't think the metal will ever corrode from the reaction of the chemical bonding that took place with the silver and sulphur or whatever chemical it reacted with to cause the change in it's original MINT STATE. PVC prevents Toning, but it will bodybag a coin because it is adherence of a foreign substance. Now with that said.... You got me even more confused, Mark... thanks a lot.

Philip

Coins come out of the mint with no toning.This, by definition, means that the most original coin should have no toning whatsoever.

Also, I am curious how red copper is more desirable than brown (toned) copper, but the situation with silver is the opposite?

ledzep87

Toning is a conspiracy man.....the government is trying to get into our heads.............

TwoSides2aCoin

<< <i>Toning is a conspiracy man.....the government is trying to get into our heads............. >>



you could be onto something

mgoodm3

Yes. Although it can be protective for the surfaces to get a little coating.

TheRaven

Corrosion, don't agree with that statement.....

Red Cents vs Brown Cents.... really I like the brown ones more, nice chocolate color

Pushkin

Tonong is generally an oxidation reaction with the metal (unless the application of something like shellac also causes toning). With some metals such as iron the main product is iron oxide (rust) and this reaction has a corrosive effect on the metal. With aluminum the usual product is aluminum oxide which forms a protective coating on the metal (the "corrosion" is only on the surface of the metal - after initial "corrosion" the reaction ceases or slows way, way down).

Toning can be both non-corrosive or corrosive, depending on whether the reaction stops or continues (slows way, way down).

Technically if you define corrosion as an oxidation reaction with the metal, then yes toning is corrosion. However, if the initial "corrosive reaction" stops or coninues very, very slowly (hundred or thousands of years) then it is not generally considered to be corrosive, and it may be considered just the opposite - e.g. aluminum oxide.

lkenefic

It depends upon the "toning". From a cursory literature search on the topic, it also depends upon the application. Industrial definitions of corrosion appear to be much different than numismatic definitions of corrosion. From a chemical engineers standpoint, both copper and silver are corrosion resistant metals...although silver a bit moreso than copper. Sulfides bond to positively charged copper atoms covalently and over time will pit the surface on which they are formed but will protect the copper underneath. This is the greenish crud you see on copper roofs and in containers used to carry potable water. Silver will form a surface tarnish as the result of reactions with oxides and to a lessre extent, sulfides. The reaction appears to be mainly on the surface of the metal and can be chemically removed without harming the metal underneath [ie...dipping]. That being said, there is a premium placed on coins that have not been wiped, dipped, cleaned, or otherwise messed around with. So... if it's "toned" I would leave it alone as attempts to clean off this tarnish will diminsh the value of the coin. To answer the original question...yes...it appears that "toning" is by definition "corrosion" or "tarnish".

Leo

Steve27

Toning is oxidation; otherwise, known as rust. Is rust a type of corrosion, I think so.

Barry

From one of the online dictionaries:

Noun 1. corrosion - a state of deterioration in metals caused by oxidation or chemical action


Toning is corrosion. There's no question about it. The metal reacts with the environment. Whether you like its appearance or not doesn't matter. Corrosion is not necessarily destructive. For example, oxidation of aluminum and copper is protective in that the compound produced (metal oxide) is less reactive than the metal itself and helps preserve it.

coinguy1

<< <i>"Noun 1. corrosion - a state of deterioration in metals caused by oxidation or chemical action".
Toning is corrosion. There's no question about it... >>

But Barry, that definition doesn't state that "corrosion- a state of deterioration" is the only possible result of toning or oxidation.

Below are the first four definitions of "toning" that I found when I looked it up yesterday - from what I have read and heard, it appears that toning can and often does lead to corrosion, but that such is not always the case, at least not within our lifetime's. In fact, as mentioned in the 3'd definition below, some believe that toning can even help resist corrosion.

By the way, I like the reply that Pushkin posted to this thread.


Some defintions of "toning":

"The coloring which has formed on the surface of a coin as a result of the metal’s interaction with outside elements. Also see: Patina".

"Color acquired from chemical change on the surface."

"Shading of color on coins. Toning can be in many forms from dark or brown to various shade of other colors. It can cover the whole coin or more often part of the coin. Toning results when the surface of the coin comes in contact with the air and environment it is exposed to. Traces of material in the metals will also play a roll in toning. Some think toning makes a "protective" coating over the surface of a coin that helps the coin resist corrosion. ..."

"Natural patination or discoloration of a coin's surface caused by the atmosphere over a long period of time. Toning is often very attractive, and many collectors prefer coins with this feature."

mgoodm3

Toning- microscopic corrosion, may stop (probably doesn't stop completely, just dramatically slow down) on its own, sometimes protective.

Corroded - macroscopic corrosion.

Baley

it's a gross oversimplification, but yes, toning is corrosion.

also, humans are multi-celled organisms and coins are pieces of metal alloy. so what?

Pushkin

The "oxidation is corrosion" definition is too absolutist.

Consider this analogy (and many analogies are false or anecdotal, but I don't think this one is (because I made it ):

"Warfarin is rat poison" - yes and no

The substance is a poison and is the most commonly used rat poison. However, regulated amounts in humans serve as a "blood thinner" used by millions of people worldwide saving countless lives every year by preventing stroke.


I think the analogy is fair for the oxidation (toning of coins). Some oxidations produce oxides that actually prevent or slow corrosion, some such as extremely high sulfur compound atmospheres cause coins (metals) to corrode rapidly. Oxidation is generally considered "bad" for steel and "good" for aluminum.

Context and result are what are important IMO, not word and phrase games.

mgoodm3

Warfarin is a poison. With the medical use you just poison people enough to get the useful effects. OD on warfarin(coumadin) is the same as poisoning a rat.

Nic

Mark, it's the lawyer in you ..... ie "have you stopped beating your wife".
Yes, it is by definition corrosion. I would like all my coins to have an original skin. Most of the older ones will be/are corroded. I like the ones where the corrosion is pleasing. K

coinguy1

K, please send that 1839 Half Dime to me so that I can thoroughly investigate whether it is "toned", "corroded" or both. I promise to get it back to you.....some.......year.

Pushkin

<< <i>Warfarin is a poison. With the medical use you just poison people enough to get the useful effects. OD on warfarin(coumadin) is the same as poisoning a rat. >>





<< <i>Warfarin is a poison >>



OK, then so is oxygen - it kills a lot of living organisms in its pure form.

Sugar is poison too if you take massive quantities of it, or alcohol, or aspirin or ....

The absolutist use of the definition is good for emotion but not for reality. Warfarin is not a poison if used in small quantities, and neither is alcohol, or chocolate, or oxygen.

Chocolate can kill cats but it usually doesn't kill humans - but you would imply that chocolate is ALWAYS a poison?

mgoodm3

Most medications function as poisons by knocking out a certain enzyme system or process. It's all in the degree. Some poisons require a greater dose to kill. One cannot generalize between humans and cats. Corrosion is the same way, it's all in the degree. If you OD on corrosion you'll have a messed up coin, if you just have a little it can be useful. Some corrosion has no safety margin - like steel.

Gemineye

Yes I agree ..it is a type of oxidation......

morgannut2

Corrosion is the oxidation of Iron compounds. It causes the cubic closest packing of the individual Fe atoms to break into oxide sheets that separate or "peal" from the remaining metalic surface, especially with the addition of water ions. Corrosion IS NOT even close to the oxidation of copper-silver componds--where sulfur is bonded-added into the matalic lattice. Hydration does not affect the new lattice, and in fact it is MORE resistant to further reactions in most cases. Rust is NOT more resistant in most cases.------------------------------------------------------
Websters is very useful for High School level definitions---but most people here know it is only a guideline once they're in College. It's edited by English professors, not science majors. Corrosion is NOT interchangable or synominous with oxidation---Do you really speak in terms of your lunch "rusting or corroding" in your stomach??? Come on--I smell an Dr White "white coins beautiful" agenda here, not a meaningful chemistry/coin debate!!! (feel free to correct my spelling ))

mgoodm3

I'm going home and am going to corrode a sandwich, Mmmm.

Pushkin

<< <i>Some corrosion has no safety margin - like steel. >>



Unless you are a metal artist that works with steel.



Positive oxidation in steel

Remember there are other oxidation reacations besides atmospheric oxidation with oxygen. Iron and coins can participate in non-destructive and very pleasing to the eye oxidation reactions. Metal artists have been taking advantage of these non-destructive reactions for centuries.


However if one decides that all oxidation is corrosion is bad, well, I'm not going to try and change the mind of an absolutist .

By the way, if someone is an absolutist, is being such an absolute?

shirohniichan

Here's a previous discussion.

TomB wrote a number lengthy posts in a previous discussion with Iwog, but I couldn't find the thread.

Basically, it boils down to toning is a sign of oxidation. Oxidation is a change in the surface of a coin. Do you call it "corrosion"? If you mean pitting and thus damage, then it is wrong to call it corrosion. If corrosion means oxidation, even if pitting isn't visible under high magnification, then one can call it such (although it would be confusing).

Gemineye

Coin Toning..........
The Real Story of Coin toning.........

BECOKA

So what chemicals are involved with the corrosive milk spots on the modern silver eagles? Also was I correct in assuming they this is corrosive.

Is this a form of toning?

morgannut2

As I understand it, some milk spots can not be removed and resulted from residual acid compounds left by the mint. If so, this would be a reducing reaction, not oxidative. So no, it's not oxidative. BUT you are correct---- a reduction reaction can also displace and remove ions--and so can be called corrosion. Rust is just one such reaction. The point again is all silver-copper toning is an ADDITION of sulfur into a strong metal lattice of elements--not removal or corrosion.

MikeInFL

Although in the strictest sense of the words I suppose toning is a type of corrosion. However numismatically, the words are used very differently. In essence, toning, for the most part, is desireable, and corrosion is not. I have gotten the impression that corrosion has caused some of the surface of the coin to be removed, and toning adheres to the surface of a coin...Mike

jonathanb

Morgannut2 knows what he is talking about. Listen to him.

grip

Here you go,read all about it.Good read.Text