Cleaning coins

[steve B]

Hung out at a stamp and coin place and did occasional work if store credit.

The level of original tarnish depends on the way a coin was stored.
Nearly every "brilliant uncirculated" coin has been cleaned at some time.
Most tarnish is pretty ugly. Just a grayish to black coating. Curently the fad is for toned coins, and yes back then there were a few with an incredible rainbow sheen. They were very uncommon, many had been in the hobby for a long time usually in great condition too. Unfortunately what was wanted then was shiny coins, so many got cleaned.
The "good" cleaning was being dipped in a product called numisol which is very similar if not identical to the silver jewlery cleaning fluid. Then a rinse with water and dried on a soft cloth to avoid scratches.

Bad cleaning creates scratches, damage, etc.


people quickly figured out that putting the coin in certain envelopes or along with certain chemicals could create that beautiful rainbow toning. So that now desirable toning is faked starting with a cleaned coin.

Considering how few silver coins I saw that were not tarnished I would expect that both of the coins shown were cleaned at some time. One well done, the other probably with some caustic cleaner.

[bnorth]

Originally Posted by steve B

Hung out at a stamp and coin place and did occasional work if store credit.

The level of original tarnish depends on the way a coin was stored.
Nearly every "brilliant uncirculated" coin has been cleaned at some time.
Most tarnish is pretty ugly. Just a grayish to black coating. Curently the fad is for toned coins, and yes back then there were a few with an incredible rainbow sheen. They were very uncommon, many had been in the hobby for a long time usually in great condition too. Unfortunately what was wanted then was shiny coins, so many got cleaned.
The "good" cleaning was being dipped in a product called numisol which is very similar if not identical to the silver jewlery cleaning fluid. Then a rinse with water and dried on a soft cloth to avoid scratches.

Bad cleaning creates scratches, damage, etc.


people quickly figured out that putting the coin in certain envelopes or along with certain chemicals could create that beautiful rainbow toning. So that now desirable toning is faked starting with a cleaned coin.

Considering how few silver coins I saw that were not tarnished I would expect that both of the coins shown were cleaned at some time. One well done, the other probably with some caustic cleaner.

I know nothing about coins. When I have seen that beautiful rainbow toning I figured it was heat that done it. I have been around a lot of metal repair and heat will do that to other metal.

[icurnmedic]

Originally Posted by bnorth

I know nothing about coins. When I have seen that beautiful rainbow toning I figured it was heat that done it. I have been around a lot of metal repair and heat will do that to other metal.

Place a silver coin in a bag with a boiled egg, and may get the same result. I would think a grader could tell the difference but I don’t know.