back to tarnishing silver

removing tarnish:




I haven't tried this, but it might work to remove tarnish from silver bullion coins?

My question is, does this process remove the tarnished silver, or does it reverse the tarnishing process?
I'd rather see it reverse the process since that SHOULD restore the luster and return the coin to its original
condition. If it's simply removing the tarnished silver, it's removing part of the surface of the coin, which
is just further damaging it. I think it would also qualify as "cleaned" if you removed material?

On one hand they say "The silver can be returned to its former luster by removing the silver sulfide coating from
the surface", but on the other hand they say "You can use chemistry to reverse the tarnishing reaction", so I
don't know whether this is removing material, or chemically reversing it?

Another source says "Using baking soda to polish silver, especially with aluminum foil and hot water, does not
remove silver but rather chemically reverses the tarnishing process by transferring the tarnish (silver sulfide)
to the aluminum." This is contradicted by another source that says it does indeed reverse the chemical process,
3(Ag2S) + 2(Al) --> 6(Ag) + Al2S3 , which does indeed remove the sulfur (S) from the silver (Ag) and into the
aluminum (Al).

It's not a perfect restoration though, since the silver won't return to exactly where it was removed, and will
rough up the surface at a microscopic level, and "is not recommended for silver coins." This is probably what
will get you a "cleaned" notation when sending such a coin in for grading. They probably place it under a
microscope and look for the tell-tale pitting of the silver.


Chemistry of Silver Tarnish & Solutions (at Educational Innovations)


Remove Tarnish from Silver (at scifun.org)

Remove Tarnish from Silver.pdf



last updated 03/26/2025 at 12:08:19 by make_www_index.command version 2025.03.04.A