2011 Gold Buffalo not .9999?

Hello,
I'm new here and looked around for a similar posting but found none. I bought some 2011 Gold Buffalos and in examining them found this spot. It looks like a foreign material in a coin that's supposed to be pure gold? The coin is still in the US Mint vacuumed package, and the material is definitely not on the outside of the plastic. Does anyone have an opinion as to what this foreign substance is?
Here is a close-up:
0
Answers
looks like a copper spot
Should there be that much copper showing in .9999 gold?
Red is typically a grease spot, grease from the minting machinery. Presumably most of that would wipe off if you could get to it. Occasionally seen on gold coins. Not especially a bad sign.
Hmmm... fine gold 99.99%.
1/10th of 1% for impurities.
That is a pretty big spot.
The melting of the gold may not have been .9999 or it might be a surface contaminant.
Thanks Bill,
Is this common? I've never seen it on any other of our gold coins.
I have occasionally seen it on better condition older gold coins. I know that I am weird, but I consider it a good sign (in terms of authenticity). It does not seem as common on moderns.
I am hoping some other folks chime in on this subject.
That's one of the worst I have ever seen! Red dots are fairly common but this... Interesting.
Copper spot and a big one for the purity of the gold.
Disagree. This is simply a reaction ring of color around an impurity (tiny black speck at center) struck into the coin.
Copper spots on gold WAS and mostly still is a sign of authenticity on gold BUT it is no longer 100% reliable.
@Insider2 It had occurred to me that counterfeiters also needed to lubricate their machinery, just the same as legitimate minters. But the red is still a good sign in my book.
Ive seen one that big before in same type of package, sigma said it was okay, and so did the refinery
Typical spot caused by minute metal particles in the air where the coin was made or packaged. Careful examination at several world mint show that the most common contaminate is silver. At museums, similar spotting can come from trace elements in dust.
This pattern is specific to particulates, not liquids.
The token is almost certainly 0.9999.
I returned a 2014 Kennedy gold half with a number of spots in blue plus a similar one to the one shown. It was a 69 in our hosts plastic. I didn't bother to test it, just returned for A pristine slabbed 69.
It’s a copper spot as it is the most common cause for spots such as this on gold. I’d rule anything else out.
Polite courteous responses! Thanks folks!
I appreciate the interaction as I have never seen anything like it before.
I'm glad I joined this site.
I would say (and agree with some of the above) it is a metallic impurity, likely embedded during the coining process...could be silver or some other metallic piece from the process....Cheers, RickO
Bought in 2014, last year found these spots. For some reason red spots can happen. Still sealed from mint.
If it would only spread to the entire coin you would have one heck of a toner!
The grease or whatever the U.S. mint used (cosmoline?) that is commonly found stuck on vintage coins is like a clear, soft, glue-like paste that scrapes right off or dissolves away with chemicals. Often it accumulates tiny metal flakes and turns gray and then darker with included particles. I made some photos just last week from an original roll of nickels and was going to post them eventually. I've got several original rolls of Franklins to conserve this evening with the same clear residue. The underlying .900 fine silver is unaffected!
I have NEVER seen grease of any kind discolor gold but if you have....
I've seen this before on US mint .999 coins. Usually hurts the value unfortunately.
Definitely a copper spot. I've had several similar spots on some Daniel Carr gold and on a 2008 gold Buffalo as well.
I knew it would happen.
Yes indeedy spotted Buff but still worth spot.
I can see a reaction ring forming on a silver or alloyed gold coin but how would it form on pure gold which should be non-reactive?
Worry is the interest you pay on a debt you may not owe.
"Paper money eventually returns to its intrinsic value---zero."----Voltaire
"Everything you say should be true, but not everything true should be said."----Voltaire
Not rare. happens to gold buffs occasionally. Strictly a cosmetic issue.
Consider it the .0001 part of the coin.
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Very common on Chinese Panda's.
Do the Canadian gold coins that are five 9's fine (.99999) have this problem? Anyone know?
Worry is the interest you pay on a debt you may not owe.
"Paper money eventually returns to its intrinsic value---zero."----Voltaire
"Everything you say should be true, but not everything true should be said."----Voltaire
None of my Canadian Cinco .9’s have the problem.