At least until they all look this way. I'll guarantee that very soon, someone who collects these coins is going to match the marks on an untoned piece from a recent (one year or less) auction with a "newly toned beauty." Unfortunately, I don't have the time to look. Nevertheless, these coins are beautiful so does anyone care if NATURAL TONING was accelerated by the "hand of man."
Believe me.. if someone could figure out how to tone gold like this, there would be a LOT more of them.
It always amazes me that people think something can't be done just because they don't know how to do it or they have never seen it before. And I'm the guy who has been telling people that gold does tone for longer than I can remember.
I am sure it is possible to AT... but I doubt there is much of it going on. These have all brought premiums. If people could do this easily, why is it not being done more?
As I wrote, give it some time... Until then, take a Pyrex glass dish, add a little "this 'n that" around the outside circumference of the dish away from the coin, then... Anyway, people have been coloring gold for over a century! Heck, if these coins were not so expensive (I owned two at one time long ago as I was thrilled to have some "Pirate Treasure" to hold.), I should go into business feeding the desires of collectors! Tempting, but I have a reputation to protect.
Just try it with a few of the 1/10th AGE like I have shown. You would only have $150 or less in them. I want to see your results. And if your results are good, I just might buy it from ya.