Porosity on coins

JoyofCollecting

What can/should be done?

I bought a wonderful, darkly toned, 1859-S seated dime with AU-55 details at a coin show last weekend. However, as noted when I bought it; it has a spot of porosity about the size of a pin head in one of the fields. It is still a beautiful coin and the price was right, so I bought it.

However, I am looking for any advice on this porosity. Since the coin is quite nice otherwise; is there a conservation service that can fix or seal this porosity spot. Or, is there something I should be doing to prevent it becoming larger? While it would be nice to "fix"; I primarily want to make sure this very small spot doesn't grow. What is the risk of growth and what should I do?

Any advice or help would be appreciated. I still haven't been able to get a clear digital picture of any coins to be able to post them to this board...sorry.

Mark

darktone

Mark- you could try NCS. Maybe post a picture here and some here might be able to help. Mike

nwcs

I don't think there is much you can do about porosity. Look, too, under a halogen light source to see if there is any green in there. That might give you a clue about whether it is expanding or not. NCS is probably your best hope.

Spooly

Are you sure it's porosity?

lathmach

That is a really rare coin there, Mark. At least a R6 in that grade. Personally I wouldn't do anything to it.
If you want to do anything at all though, have NCS look at it as darktone has suggested.
I'd also look at getting it authenticated for peace of mind if it's a raw coin.

Ray

Gilbert

If you truly have porosity on this "dime" then you should definitely have it looked at by NCS or someone you would trust to ensure it is not susceptible to further erosion.

JoyofCollecting

I appreciate all of the good advice. I am sure it is porosity; however it is so minor that I want to make sure it can't spread. It truly is smaller than the period at the end of this sentence. As far as authentication; I feel pretty confident as to it being original. The deep "black" toning is consistent with the manilla holder that the coin had been stored in. I bought the coin from one of the top liberty seated dealers in the country who had purchased it from Heritage as part of an estate lot. If NCS is able to "fix" the porosity, I will try PCGS for slabbing. Otherwise, I guess it will go into an ANACS holder.

Again...thanks for the help. You guys are great!!!

Mark

hughesm1

If you got the NCS route, why not submit it to NGC? After all, they are right next door to NCS

Pushkin

If it is porosity then there it is almost certain that there will be pitting. For physical repair you may have to turn to a professional coin repair expert. I know one was listed on several threads not too long ago, but I can't remember his name. Perhaps someone else can help. He will most likely have to fill in the pit and "fix" the repair spot. I believe PCS will essentually perform non-destructive cleaning and chemical enhancements similar to dipping, but not physical repair such as filling in the pitting that results from porosity and verdigris. Anyway, just a thought.

Good luck.

JoyofCollecting

Pushkin:

Thanks for the advice. There is no pitting...so I might be wrong about the porosity. As far as NGC, won't both PCGS and NGC bodybag a coin with porosity?

Mark

airplanenut

Rare coins can get special treatment- look at some of the really old bust coins they slab- many have been cleaned and end up in PCGS slabs because of their age...

Also, if it is that small, they might overlook it and drop it a point.

Jeremy

PS- I agree with the others- NCS would be a smart guess, then slab it so it is under a guarantee if it does happen to spread.