What causes the “Greenie” look on old copper?
CircCam
Posts: 282 ✭✭✭✭✭
I was told recently the look is prized the EAC crowd (the veracity of that, I have no idea) and would like to know if there are any credible theories out there for what sort of storage caused it. I.e., the sort of notes that were written on flips that are usually long gone when buying certified coins these days.
I’ve yet to have any dealer who has examined this coin in hand accuse it of being AT or messed with but those opinions won’t offend me either, just seeking knowledge from those with more years in the game than myself. I’ve seen plenty of blue and purple copper but very rarely see this look.
Side by side photos courtesy of @robec
Thanks.
28
Comments
True reds and greens are hard to produce with AT techniques, so I think this is prized because it is indicative of slow natural toning and not cleaned and retoned and not from improper storage.
Mr_Spud
I dunno, maybe 172 years of being exposed to various environments, humidities, and temperatures?
Just my guess.
30+ years coin shop experience (ret.) Coins, bullion, currency, scrap & interesting folks. Loved every minute!
To be sure and agreed, there’s no way of knowing for sure- just seems like the average result of that is an even brown toning with subdued luster, so when I look at this thing and it’s green and blazing luster despite the thick skin it made me wonder if there was something (anything) known about the storage medium. Similar to how it’s a known thing with tissue paper toning on IHC proofs, paper envelope multicolor toning on silver, etc.
Great point though, could be a variety of things over its lifetime, roll the dice and some survive thus.
No idea, but I’ve likewise assumed @Mr_Spuds explanation of slow, natural toning, (coupled with right coin surfaces in the right environment), was the reason.
I do know they’re pretty darn scarce. I’ve owned a fair share of nice large cents, and looked at many hundreds over the years, and seldom see true greenies.
My lone example:
I have also seen "greenie" used as a metal detecting term to describe the effect of a copper coin pulled from the ground under just the right circumstances. It gets a dark green glossy look, and can be quite appealing if it doesn't have any corrosion or crusted on dirt. I have found some Indian Head and early (up to about 1920) wheat cents that look like this.
Young Numismatist • My Toned Coins
Life is roadblocks. Don't let nothing stop you, 'cause we ain't stopping. - DJ Khaled
Wish I still owned her. Bought many years ago from Wayne Herndon.
Here's a starter coin sporting some greenage. I just give it free will.
https://d1htnxwo4o0jhw.cloudfront.net/pcgs/cert/44127878/233807031.jpg?v=1722131895692
A bit of green on this lustrous piece, but not an acceptable shade.
30+ years coin shop experience (ret.) Coins, bullion, currency, scrap & interesting folks. Loved every minute!
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That would be more than "acceptable" to me.
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I think they said that because it got QC by PCGS. But I like the look as well, and seeing the other ones posted, this one looks like it would fit in with the rest.
Young Numismatist • My Toned Coins
Life is roadblocks. Don't let nothing stop you, 'cause we ain't stopping. - DJ Khaled
@dcarr
@hummingbird_coins
Quite acceptable to me also, and, yes, QC at our host.
I was happy to buy it in an ANACS MS63 holder, and the (2023) Trueview captures the coin perfectly.
30+ years coin shop experience (ret.) Coins, bullion, currency, scrap & interesting folks. Loved every minute!
Green is the natural oxidation color for copper, my bay window copper roof went from bright copper red to green. Even the Statue of Liberty turned green over time. Not sure why QT. I like the 1851 cent also.
My guess is that pink areas peeking through gave the graders pause, that it may have had an old dipping.
Entirely possible that it was dipped, in some substance, at some time, in its 173 years. Maybe for a few decades it even had that ‘pink’ dipped copper look, and overcame it through the magic of chemistry!
I like it for its lustre, lack of marks or spots, and the fabulous colors that it has (somehow) acquired.
30+ years coin shop experience (ret.) Coins, bullion, currency, scrap & interesting folks. Loved every minute!
Glistening, even chocolate color on obverse and reverse of Unc. BN Large and Half Cents is as good as it gets, which is why EAC people like it.
"Seu cabra da peste,
"Sou Mangueira......."
Tarnished (like oxidation on a bitten apple) seems to me, to be a fluorescent scar sometimes preferred.
I've read post's that stated "a green hue of a toned coin is rarely composed",
Something I would like to add. "the green hue, WITHOUT, some kind of scar, also, is rarely composed"
This smooth shade of green borders green/blue (327 in a pms book) and darker.
But......Eye appeal is a royal flush.
Green is the “final stop” in the oxidation process. Takes decades of sitting undisturbed as far as I’m told. I have never seen a green toned copper that seemed AT to me. Here are a several of mine:
Empty Nest Collection
Matt’s Mattes
Interesting post. Here’s a few I have:
“The thrill of the hunt never gets old”
PCGS Registry: Screaming Eagles
Copperindian
Retired sets: Soaring Eagles
Copperindian
@renomedphys
Good point in that the copper needs to be undisturbed after mintage. Once circulated with dirt, grime, finger oils, etc., it usually just turns a dark brown color.
Thanks for the input so far, all and for sharing green toners.
Makes sense and sheds some light on a coin I used to own. I had this in my collection for awhile and when I shared it received a gobstopping offer, so I let it go. Another guy came along and said he’d have paid me twice the moon money offer I took. Perhaps the scarcity of green toning combined with what was then a low pop in BN.
@CircCam: yes, but it also has great eye appeal!
“The thrill of the hunt never gets old”
PCGS Registry: Screaming Eagles
Copperindian
Retired sets: Soaring Eagles
Copperindian
Green eye appealing, with style.
What ?
MAN O MAN do I miss owning that 1852 greenie! No joke about the luster. Its a total blazer in person and hardly has a mark anywhere on it. Debate aside, its truly beautiful in person and hard to stop twirling in hand.
Jbknifeandcoin.com
IG: jb_rarities
My only certified copper so far. It has a little bit of green.
Young Numismatist • My Toned Coins
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MPL's - Lincolns of Color
Central Valley Roosevelts
I love dark, lustrous copper like in the OP.
Type collector, mainly into Seated. -formerly Ownerofawheatiehorde. Good BST transactions with: mirabela, OKCC, MICHAELDIXON, Gerard
I liken the green toning much in the way aluminum stays shiny. It is likely the result of a thin layer of oxidation that prevents the deeper atoms, molecules, etc from also toning.
The OP coin is a fabulous example!
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Sold this a few years ago at FUN a regret it.
"Got a flaming heart, can't get my fill"
It appears this thread has put me in a green copper mood. Just purchased from eBay:
Young Numismatist • My Toned Coins
Life is roadblocks. Don't let nothing stop you, 'cause we ain't stopping. - DJ Khaled
It’s a form of tarnish as a result of reaction to the atmosphere. In high humidity areas can be more severe. Move them quickly lol.
A greenie in an OGH. Dealer wants a 2x retail premium for the color. I think it is worth it.
Love the 360 deg. die crack.
Lots of green there: green coin, green label, green sticker. If I were you, I would "snap" up the offer.
Young Numismatist • My Toned Coins
Life is roadblocks. Don't let nothing stop you, 'cause we ain't stopping. - DJ Khaled
Found another partial greenie among my hoard the other day. Unfortunately it’s only on the reverse: