Will red copper eventually be brown ?

On 11FE03, NGC announced that it would begin to guarantee grades on copper, bronze, and copper-nickel coins for a time of 10 calendar years from the date of the NGC grading. before that, there was no grade guarantee for those coins. Of course coins slabbed prior could be submitted for reholdering.

Clicking on the "PCGS Guarantee" link on their site only lead to some rather vague verbage that I could see being taken to mean either way that they would guarantee or not guarantee the color.

Anacs grade guarantee applies as per their line: "This Guarantee applies only to ANACS-graded platinum, gold and silver coins."



My opinion is that the tpgs do not seem overly confident in the medium to long term protection afforded by their slabs for grades of copper, bronze, and copper-nickel coins, so it may be mostly wishful thinking that such slabbed coins will retain their color indefinitely. It may well be conducive for color retention for the coin to be slabbed, but evidentally results are not favorable enough to offer a long term guarantee. Some other methods, such as intercept shields may offer better protection.

 

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Yes, oxygen is needed to brown the copper. Not to say that a coin won't brown in a holder(I'm not sure), but I do believe many coins will remain red indefinitely in a slab. Copper turns brown when it reacts with oxygen, particularly in the presence of sulfur, to form copper oxide.

True, but you would think they would offer something so your coins stay shiney your whole life time, I am personally a paranoid person so I store my coins in an airtight box that has a dehumidifier and CO2 pumped in to replace the air, exept for my toning coins which I leave out in random places so they will get vetilation and light for toning.

The above is somewhat misleading. "particularly in the presence of sulfur" or " CO2 pumped in to replace the air"
The facts are as follows. When Copper is exposed to MOIST air it slowly reacts with the Oxigen to form Cu2O. This IS the start of the Copper discoloration. Then the Cu2O begins to react with any CO2 present to form [CuCO3-Cu(OH)2] known as Copper Carbonate. This is a slight greenish discoloration on the Copper coins sometimes called a Patina. NOTE! so far no Sulfur is required to do anything.
Now if there is any Sulfur in the area in the form of H2SO3 or H2SO4 it will react with the Copper Carbonate to form CuSO3 or 4. SULFUR DOES NOT REACT WITH COPPER directly. These are normally air born acids due to a Sulfur burning invironment such as a power station or steel mill. The Sulfur released is SO or SO2 and in the air combines with moisture (H OH) to form air born acid and during rains sometimes called acid rain. Note! (H OH) is the Hydroxide commonly known as H2O or water.

Sorry for the chem lesson but that should clear up copper presevation a little.

 

seems inevitable it's going to turn from what the grading guarantees are. Maybe we shouldn't pay way more for red ?

 

This is the conclusion I've come to as well. For modern stuff where red is easily and cheaply acquired then i prefer red, but I am hesitant to pay multiples for red coins when I am not certain that I will be able to keep them red.

 

This was a good thread, thanks for the feedback.

 

Here is a brilliant old copper coin. http://cgi.ebay.com/GEM-1853-LARGE-...0QQihZ021QQcategoryZ11950QQrdZ1QQcmdZViewItem

 

very nice !

I wonder what kind of population exists of any US copper 1855 and earlier.

 

NGC will show the population on their web site, I do not know how far back they go however.

 

I saw some earlier reds listed, oldest I recall was 1818, I think. Pops were very low, but you can't tell much with only one service and resubmissions.

 

Interesting discussion... and thanks for sharing those really nice examples.

 

Did you buy this, or build it yourself? Also, is it inexpensive? Sounds like a pretty awesome setup. My coins are stored in a firesafe box, at my parents house, since I forgot to bring the few coins I didn't sell with me to California.

 

i think the best thing to do is to get it slabbed with the most air tight container youcan get, and keep the coin of of well circulated areas.

it will eventually turn brown, but it will go slowly in a slow environment

 

I was wondering about that system myself.

 

We bought a slabbed Ngc ms68 red 1898 red-simply beautiful. We pulled it out to look at it after 6 years -just last week-- it is BROWN. W H Y ?????!!!!!!

 

Hope, Zaneman's post was from 2006, but yes, what happened to yours can happen to most. Main factors: time, slab seal, environmental factors in the air, storage procedures. There are many threads that mention these factors on CT, try the "search" feature at the top under FORUMS, Search forums. Some problem areas are : High moisture, manufacturing or acid/sulfur(coal) in the air,etc.

Since I live in a low humidity area with little manufacturing or use of coal, I have less problems than many. But I check all every year or 2 for any beginning problems. Sorry about the coin, copper is extremely sensitive to color change.
Welcome to the forum, Jim

 

That is the reason why I'll only buy BN copper coins, plus IMO chocolate BN is the best looking color.