Fire Damaged Coin

Usually not possible, or worth it. Post a pic and we can tell you what to attempt.

Yeah, first we need to know what you mean by burnt and secondly, what the coin is...

For example, is it a nickel 50Rpf or 1RM (1933-1939), Silver 2RM or 5RM, Copper based 1, 2, 5 or 10Rpf or the later 'wartime' Aluminium or Zink types...

And when you say fire damaged, what do you mean? Discoloured or actually damaged - if the thing is actually damaged by fire, there's not much you can do about it and odds on (with one or two VERY rare exceptions) the coin will be for all purposes, worhtless (trust me, Third Reich era coins generall are not as rare as ppl like to tell you!)...

As Sap says, Zinkmünzen very quickly take on a dark shade when handled in circulation - this is just the nature of the material and its oxidsation process; silbermünzen can very quickly turn BLACK if they're exposed to anything higher than trivial concentrations of Sulfur, an extreme yes, but still a natural reaction; if copper and aluminium coins are 'black' due to heat or corrosion, they're probably past the point of help; while nickel is usually pretty resilient. It has a really high melting point and has very good anti-corrosion properties...

Now at the other extreme, there is the 'Stuttgarter Brandschuttproben'; a number of exceeding rare proben coins and medallians that were damaged by fire when the Stuttgart Mint was struck by allied bombs in 1944 - there were 'lost' in the rubble for years, until a scrap merchant purchased the rights to recover scrap metal from the site and then years later, discovered what he actually had found! Needless to say, he became a very rich man!

If (despite the ridiculously long odds that) by 'fire damaged' you're referring to a Brandschuttprobemünzen, don't do ANYTHING to it! You don't need to 'restore' it...

But yeah, we need pictures! :)