ageka Posted June 16, 2005 Report Share Posted June 16, 2005 Acetone has never caused a reaction on any metal I've dipped in it. It's an organic solvent, not an acid or alkali. .900 fine or .917 is what all the old gold coins I have are. I've never seen any struck in .580 which is what 14k works out to be. That would be kid of a debased alloy for coin gold. Maybe you should try the jeweler's standby of a strong solution of sudsy ammonia on the paint spatters. That seems to clean a lot of things from jewelry, even adhesions that have resisted other cleaners. 28 plain I heard about ammonia for silver I think What is sudsy ammonia ? is it concentrated ammoniumhydroxite NH4OH ? Quote Link to comment Share on other sites More sharing options...
ageka Posted June 18, 2005 Report Share Posted June 18, 2005 I read in a German forum that a several 9999 german gold coins had red spots A university investigated them with X rays and established the spots were 84 % silver 10 % copper and 5 % gold and were probably silversulfide It was assumed the spots were only a few molecular layers thick and were impurities of the planchet makers who made silver blanks and gold blanks So assuming my coin is spotted not with acrylic paint but with silversulfide I seam to find that one of the possible treatment is citric acid µ I know nothing about silver any suggestions ? Quote Link to comment Share on other sites More sharing options...
gxseries Posted June 18, 2005 Report Share Posted June 18, 2005 I read in a German forum that a several 9999 german gold coins had red spotsA university investigated them with X rays and established the spots were 84 % silver 10 % copper and 5 % gold and were probably silversulfide It was assumed the spots were only a few molecular layers thick and were impurities of the planchet makers who made silver blanks and gold blanks So assuming my coin is spotted not with acrylic paint but with silversulfide I seam to find that one of the possible treatment is citric acid µ I know nothing about silver any suggestions ? Yuck, that is very horrible. Must be some horrible silver/copper plating devices used to strike the gold coins. Bad quality checking. Citrus acid wouldn't necessary help, as it may dissolve some of the copper away, but it will not do anything with the silver. I was about to suggest nitric acid, but I REALLY don't know the results, as it does seperate the silver off from gold too but I don't know how the final result would be like... Geez, what kind of coin do you have there ageka? Quote Link to comment Share on other sites More sharing options...
ageka Posted June 18, 2005 Report Share Posted June 18, 2005 Yuck, that is very horrible. Must be some horrible silver/copper plating devices used to strike the gold coins. Bad quality checking. Citrus acid wouldn't necessary help, as it may dissolve some of the copper away, but it will not do anything with the silver. I was about to suggest nitric acid, but I REALLY don't know the results, as it does seperate the silver off from gold too but I don't know how the final result would be like... Geez, what kind of coin do you have there ageka? I got microspots that only show up under 10X maginification but that german forum has a pic of a 1 gram minibar with a huge red spot I was told the citric acid woud remove the silversulfide Nitric is too dangerous for copper content of 10% in the spots first pic on the page http://www.goldseiten-forum.de/thread.php?threadid=1849&sid= Quote Link to comment Share on other sites More sharing options...
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