Add A 'Dipped' Problem Coin Modifier

When I dip I use Copenhagen.

But seriously, E-Z-est coin cleaner is a commonly used dip. A quick dip and thorough rinse is hard to detect on mint state gold and silver coins.

Improper cleaning is a tough term to define. We have a Morgan grading thread running right now that is a good example of a harshly cleaned coin. I recently bought this quarter-eagle for cheap (near melt) because it's "Improperly Cleaned". Both the Morgan and this piece would be "Improperly Cleaned".

Silver "dip" is typically made of a mild acid, such as citric acid or sulfamic acid, combined with thiourea, the active ingredient that reacts with and removes the silver sulfide that causes tarnish.


Slabland overgrades by Australian standards, but not by US ones. And you're probably correct in your grade conversion; I find that to convert US grades to ours, subtract one and a half to two grades. The problem comes about when the unscrupulous try to sell US-graded coins for Australian-graded prices.

Am I the only one that's having trouble identifying the improper cleaning?