White Specs Or Flakes On Early American Copper Large Cents And Half Cents

Copper is a very reactive metal. At least compared to gold or silver. Could be lots of things. As far as effect on grade and value, eye appeal is very important to most buyers. Spots certainly aren't going to add any value. As far as detracting, are they subtle, or very pronounced. Limited to the fields, or all over the design?

Effect on grade is probably less of an issue. As I've seen very ugly spotted coins still grade high. Might knock it down a point or two if really bad, but still superficial. But a high grade doesn't really matter if nobody wants to buy it.

If the spots are more than superficial. Have damaged the surface under where they are, they yeah, probably a details coin, and a huge effect on grade and value.

If it's a high value coin, you could run it through one of the TPGs conservation services. Assuming the spots are superficial. But copper is kind of a crap shoot with that process. Can easily make the coin look worse.

I've seen this on copper coins as well, sometimes I think it's usually some sort of foreign substance or even lint that adheres to oily copper. I've run into it on some of my Two Cent coins and have always been able to remove it through acetone soaking and a mix of air blowing. Now it could also be from impurities in the metal composition itself and is showing up and reacting or oxidizing differently than the surrounding metal.

Photos would help us to better understand the issue I'm sure.

I suspect it's specks of cardboard dust sticking to the coin, more visible on a dark-surfaced coin.

Owner had a dandruff problem?

to the CCF!

Popcorn ceilings can yield that white flake effect ....

Seriously though, I've found the "Coin Care" product to be great for neutralizing and conserving the old coppers, in particular. All manner of residue tends to collect over time; especially so, within the recessed regions of counterstamped coins. IMHO, the fewer contaminants residing on coin surfaces, the better.