Patina And Value

Hello.
My opinion is that harsh cleaning greatly affects the numismatic value.
Especially if you take off the patina.

I really don't know the answer to that. But I have some ideas.

I'd say around 25% to 75% depending on condition. Some coins have solid metal surfaces under the patina. Some have a nasty looking surface but still solid. Some have mushy looking surfaces and some with a unstable core that's possibly corrupted. Some have serious damage, like the coins I've seen after Electrolysis.

Regardless, those guys need to learn how to clean coins less aggressively.

I will say that it decreases the value 50 - 90%. It looks like electrolysis was used. I would definitely tell the group that they should change their cleaning method(s). Normally I will not even look in the zapped bin.

Same here, for the right prices that reflect the overcleaning.

jwharper: As you may well know, almost all ancient coins have to be cleaned before they can be marketed.
This forces a dichotomy to be considered. The cleaning of long buried ancient coins almost always affects the patina. You would expect that. Therefore, expert cleaning is needed with potentially valuable ancient coins.

Eye appeal is just one of the factors to be considered when valuing an ancient coin, and patination is a part of eye appeal.
Ancient coins are a bit like evaluating humans, which has to be done at job interviews. All of the factors have to be taken into account and an overall comparative value arrived at.

The best thing to do is to compare your valuing efforts with the commercial experts. If I am to buy an acncient coin, I always look at the VCOINS website, to get an idea of comparative pricing. In my case that can lead to buying the vcoin offering instead.

All coins begin repatination after being cleaned, and I suspect that some ancients have boosted artificial patination applied to them.

One thing is for certain: It is a sure bet that not everyone will agree with the valuation you give each coin. We all consider different aspects of an ancient coin's good and bad points, with more or less importance.

The best approach would be to ask yourself:
'How much would I pay for this coin if I wanted it for my own collection?', then ephasise that it is your opinion only.

jw, went back and checked it out, being a noob, I feel I'm getting better at attributing these coins, but do have a way to go...your the Man.......
I will email you for some pic's, I like coins well centered, but I do like coins, broken, out of round, different....as long they have good detail...like the pic below...Thanks Eng...

Sel: that is how I am approaching the value of these coins; however, I wanted to hear what you and the others had to say on the subject. I value all your opinions.

So far the club has sent me 25 images. I have them attributed and linked to images on line of a like coin. I have not sent my report back to the club only because I have not offered a value yet. That's next. Thanks to all for your input. And, once again, if anyone is interested, I can forward the images for your consideration. Remember, though, these are not mine and I am not even in the same country as the owners.

Nothus has a good point. A $10 coin with a signed letter from the finder giving the date and place of the discovery would become a $20 coin. Many of us would like to have coins with full information.