Hi! I have a ancient coin that I bought on eBay and I wanted to know of it is authentic or not and some information about it. It’s a copper as of Claudius.
Looks authentic and possibly tooled as @iamtiberius points out. If it is tooled, then this would be to raise the portrait and the reverse so they are legible/attributable. It is also possible that it is not tooled, as tooling is very common with the highest grade coins, not so much with lower grades.
I agree with @iamtiberius that it looks authentic. Instead of tooled... I think it's probably just had some fine "dirt" added or it was cleaned to leave just enough dirt to enhance the worn details.
It's been my observation that, at least with bronzes, many more mid-to-low priced bronze Roman coins are tooled than high-price coins. I rarely see tooling in high-priced bronzes -- at least, in ones that are actually purchased. The reason for this is clear: if a collector is willing to pay high prices (e.g., $5,000 - $50,000+) for a high-quality bronze, that collector is also unlikely to accept tooling on such a coin. As for the OP coin, I think it's possible that the coin was originally tooled to bring out what little detail is still in the legends and devices, and then artificially patinated with sand to make the legends and devices stand out while obscuring the tooling that was done.
The OP coin appears to be of this type: Claudius (41-54), As, Rome, AD 50-54; AE (g 11,82; mm 27; h 6); TI CLAVDIVS CAESAR AVG P M TR P IMP P P, bare head l., Rv. LIBERTAS - AVGVSTA, Libertas standing r., holding pileus and and extending hand; at sides, S - C. RIC 113; C 47. The above coin was sold at auction by Bertolami in May 2015 for $34 not including buyer's fees.
I don't see any actual evidence of tooling on the OP coin (though it could be). It looks like the so-called "ghost" coins in which the devices are visible because of fortuitous sand patina, but not the fake sand patina common on eastern bronzes.
I am wondering how you detect if a sand patina coin has a fake patina because I have a bunch of them with a sand patina. I am hesitant about soaking the coin in water because it could ruin the coin even if the patina is real.
If the patina looks "painted" at all then it could have been tampered with. Sometimes unscrupulous folks will add the fake patina to raise the details and the portrait of the subject. I've got a bunch too and I don't think I have any that are inauthentic, so you are probably OK.
I don't think the OP coin is tooled. These Claudius middle bronzes were pretty boldly struck and circulated a very long time. I think it's just worn. An easy way to tell if the "dessert" patina is real is by looking at the sellers other coins. If they have 100 LRB's and all have the same color and consistency sand patina then it's probably fake.
Doesn't look like he fools around with fake patina, the coins are all low grade. I think you're good. For your first Roman coin you got a 1st century Claudius...that's better than I did!
I was going to say that its a typical coin found in Spain or England. Looks possibly barbarous, then I checked the link and saw the seller is indeed in Spain. I think its genuine, not tooled, but probably re-patinated.