Are there any products that deal with these kinds of spots effectively?

Bodin

coinbuf

Your coin has dandruff. But I doubt that head and shoulders would work.

Goldbully

Looks like real frost. ❄️❄️❄️

Sapyx

Have you tried penicillin?

But in seriousness, it looks like plain ordinary tarnish to me - just in an odd, biological-like pattern. Regular tarnish-removal treatments ought to do the trick.

I should add: I've assumed this is a silver or silver-clad half dollar, rather than cupronickel-clad? "Tarnish removal treatments" will likely destroy a cupronickel coin.

Bodin

@Sapyx said:
Have you tried penicillin?

But in seriousness, it looks like plain ordinary tarnish to me - just in an odd, biological-like pattern. Regular tarnish-removal treatments ought to do the trick.

I should add: I've assumed this is a silver or silver-clad half dollar, rather than cupronickel-clad? "Tarnish removal treatments" will likely destroy a cupronickel coin.

Did an acetone bath to no avail. It is a '68 silver-clad.

Namvet69

Honey, where'd we put the snow chains?

Sapyx

@Bodin said:

@Sapyx said:
Have you tried penicillin?

But in seriousness, it looks like plain ordinary tarnish to me - just in an odd, biological-like pattern. Regular tarnish-removal treatments ought to do the trick.

I should add: I've assumed this is a silver or silver-clad half dollar, rather than cupronickel-clad? "Tarnish removal treatments" will likely destroy a cupronickel coin.

Did an acetone bath to no avail. It is a '68 silver-clad.

Acetone won't remove tarnish. You'd need something like E-z-est dip, or the baking soda and aluminium foil method.

Cougar1978

Try dripping it in jewel luster or whatever. Good luck. From the consistency of the stuff looks like some kind of biological attack or splash of some substance.

Mr_Spud

@coinbuf said:
Your coin has dandruff. But I doubt that head and shoulders would work.

That’s a good one, but Selsun Blue just might do the job and leave you with some pretty rainbows 🌈 (if u know u know)

Mr_Spud

You might want to try some MS-70 before trying the E-Z-Est or Jewel Luster. It’s less harsh than those and sometimes works.

dcarr

That might also be a permanent etching of the surface due to a chemical reaction with something (such as PVC).
If that is the case, nothing will help it.

But I would still try (in this order):

1) Water.
(people tend to forget that water is a solvent and it will remove water-soluble contaminants that acetone won't touch).

2) Acetone or similar solvent.

3) traditional coin "dip" cleaner.

logger7

MS70 is good with Unc. coins. Tried on this one recently:

lilolme

When I saw the OP picture I knew I had seen similar previously. Did a couple of searches and not much. Did find this one but I am fairly sure there are more as I recall.

https://forums.collectors.com/discussion/comment/11968247/#Comment_11968247

seatedlib3991

Any way you can post pictures of entire coin?

coinkat

Merry Christmas Charlie Brown…

Seriously… there almost seems to be what could be milk spots on the coin which could be the reason the request for a complete picture was made. Look at the space between and within DOL

7Jaguars

Hmm, I like the Sapyx method above which is technically a chemical reduction. More than 40 years since college chemistry but that is a silver salt [oxidant] on the surface.

Some examples of silver salts are the halides, silver chloride, silver bromide, silver fluoride, etc.