I have only been collecting ancient coins for just over a year - so I do not have enough knowledge or experience to make any solid determinations on my own. This is an undeniable fact. However I think I am intelligent enough to see patterns and curious enough to ask more experience collectors for help. I hope you will help me. I have read an old thread about a certain seller with "sand" patinas and the thread got rather nasty... I am NOT looking to revive that discussion.. however there are sellers on VCoins which feature sand patinas and others with red/clay like patinas, very green patinas that seem to dominate their offerings. Is this a concern? Am I buying a coin with "makeup" covering faults? I do not want Dealers named on this thread. If you feel there are Dealers I should avoid a PM would be appreciated. I would just like to understand how an experienced collector navigates this - are my concerns bogus and they are just sourcing their coins from a particular region?
I think the key is to look for consistent patterns in these dealers' inventories. If ALL or nearly all of their coins have consistent patinas and/or coloration, there's a red flag. In the thread you mention, I recall some pretty damning near-poster-sized lineups of coins from two particular dealers; one with all reddish patina and the others all orangeish. I have not since purchased from either of those dealers, though I did business with one of them previously (with a cheap coin) and was satisfied. Though I've dabbled in ancient coins a little bit for about twelve years now, I'm basically still with you in the "novice" boat. I'll admit I was pretty ignorant of the patina problem before that thread. I think that once you look at enough coins over time, you develop more of an instinctive sense of when something is just not right. And that's really all I can say on the matter, since like you, I'm not fully there yet. I rely very much on trusting the dealers I do business with. Stick with the ones with a good reputation and I think you'll be fine. And I do think most - almost all- of the ones on VCoins are OK, really.
Definitely maybe. Coins from similar areas tend to have similar patinas. Coins from the middle east will likely have desert patinas. Most of the coins I've found from, for example, Viminacium tend to have bright green patinas. So a dealer from the Middle East who deals exclusively in coins found locally is likely to have coins with similar desert patinas. But I have received coins that appeared to have a desert patina, but the patina rubbed off with simple handling. Obviously, this was a fake patina applied to, if not conceal damage, certainly to enhance the coin's appearance. Furthermore, there are numerous products out there that some dealers apply to coins to darken them or fill pits and scratches. This is particularly common with dealers who use electrolysis to remove corrosion from coins. On several occasions I've received coins that were covered with something about the consistency of shoe polish that, again, was easily rubbed off. All of this is dishonest, in my opinion, and I've never done any repeat business with anyone who knowingly sold me an artificially patinated coin. Nor should anyone else, as far as I'm concerned.
Since you are learning, it is only adecuate to point out that the actual patina is the mineralization of the coin´s surface in contact with the environment. What we are calling here "patina" (wrongly, but of common use, since we know the difference) are the sand or soil deposits that remain attached to the coin after cleaning it. What Marcovan and Glenn are saying is true, just wanted to give you a tip of knowledge.
