Difference between red and brown copper toning?

Chill. Wheres the love Buddy

 

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Boarder line thread highjacking I’d say. Some one get a rope!
Hey don’t fight it just start a new thread. Looks like you have
some good research just post it on your new thread and see
what kind of responses you get @Buddy Love

 

All the colors I previously reported in terms of copper colors I have seen in worn down corroded Large Cents or copper U.S. Colonial State Coppers. Chlorine and sulfur in combination with copper creating this myriad of compounds producing these different colors of copper compounds mostly copper oxides/sulfides/chlorides. For the average collector what does it matter and the one just collecting slab Lincolns in the 20thC. This is a very small spectrum of observation involving just one oxide of copper = RED = the color we all LOVE in copper coins regardless of the Century we collect ... LOL. JPL.

 

Whoa I had no idea this thread was still going. I think my original question/thread was a bit of a cluster. Half mixing scientific wonderings with my layman's understanding. So I can understand both kinds of responses--and welcome both.

Thank you GDJMSP (as always)...

And thank you Buddy Love (please dont leave

And thanks to everyone who is here to teach and help...


I believe I thought that red was untoned copper through various shades of toned copper until it reached brown. Like say its salmon to begin with and now is orange...I still consider that red. Why? Because this is what Ive observed--my observation could be incorrect. It looks to me that many coppers in slabs are RD but are NOT the color they were Day One...I am going to have to restructure my whole way of looking at this if it is not correct. Are you saying the moment copper tones one shade away from what it was the moment it was minted it is no longer RD?

My experiment was with a handful of random cents...some pre-82, some post-82, some cleaned, some unc...It was far from scientific!

 

You know...I am still wondering about this lol. I was Googling some more still trying to figure it out. I came across my own question and re-read it with fresh eyes. Such a hard question to ask--to convey.

I wouldn't open this back up but for seeing a means to help me ask the question better in GDJMSP's last reply where he says. "...darker shades of red are often still given the Red designation." This is what I want to know about. These darker shades of red. A coin is newly minted. It goes through these darker shades of red. It becomes brown. Does it become brown because of the same forces that darkened the red to "darker shade of red"? Is it all cupric oxide? Or are different kinds of oxide causing different colors: cuprous = "darker shades of red" and cupric = brown/black?

Maybe I need to take a chem class

Maybe this thought experiment would help. Imagine you want to watch a newly minted copper coin go through all these darker shades of red all the way until it is a common brown coin. Could you set up a single set of conditions that could accomplish this over time? Or would you need two different sets of conditions--one to go through the darker shades of red and then another to turn it brown? Is brown just the darkest shade of red?

Probably just confused things more. My apologies for not knowing I simpler way of asking this. Dont hate me!

 

Time.

Eventually they all patina to this:

 

Several years ago (maybe many, depends on perspective) there was an attempt by folks at the SLCC and others to describe "RD" more thoroughly since RD encompasses such a wide range of shades. IIRC, RD was broken down into a 4 or 5 point range. Thus RD1 was "fresh mint red", and as the coin toned toward brown it passed through RD2/3/4. Eventually the darkest red color still considered RD was RD4 or RD5. I still have 2x2's graded according to obverse and reverse RDx designations.

The concept never really caught on. Probably too subjective.

 

It's probably a lot more complex than just simple oxidation. There's a lot of stuff floating around that loves to react with copper. So it may depend on where he coin ends up. Plus some of the color change may be due to the thickness of the patina as well as it's composition.

I think there just too many variables to provide a simple answer.

 

Hey, I have an advanced degree in Chem and couldn't answer this...too many variables.

 

That's why I tried to give the thought experiment. Set up whatever conditions you want that will take a freshly minted coin through the darker stages of red. If left in those conditions will the coin ultimately turn brown?

 

yes...ultimately, then possibly green.

 

GDJMSP Numismatist Moderator
paddyman98 said: ↑
It's not actually the color red.. It's just a numismatic term. Strange right?
Here is a chart for you
That chart isn't worth the combined face value of the coins pictured in it. No offense intended to you personally paddy, but I say that because there are only 2 coins in that chart (the 1st 2 left to right) that even qualify as Red.



If the toning has a Red tone then it is still considered RD.

 

I find it interesting that folks are saying that fresh cents are not "red". As a numismatic photographer, I can tell you emphatically that they indeed are very red. The R channel is very easy to over-expose with Cents, and to keep true color it's necessary to reduce saturation and overall exposure.

 

For hundreds of years the term "red cent" has been used. New Cents are a strong reddish shade. To say they are not even close is simply incorrect.

 

Air, and temperature swings from cold to warm?