The lustrous denarius - polished, covered, or natural?

[Anachoret]

Why denarius looks like new nickel? 
Is any dealers covering silver coins with something, or polishing to make them shining?
This theme has arisen recently on one forum of ancient numismatists, as many collectors began to pay attention to unnatural shine of high-grade silver coins coming from some dealers (US mainly). Such coins are shining, and has completely uniform color like nickel. There was even a suspicion that they are covered by something. I am interested this question in connection with denarius recently received from very respectable dealer. It is very bright in reality, not only on photo. The surface under a microscope looks like a mirror. I wish to define, is it some especial action of dealer to make the coin so shining, or not. What do you think about this?
The fragment of photo from dealer (right); the same fragment, but more realistic (left)

[gavignano]

Hi. We have discussed this before, at that point people thought the coins were highly polished. They showed up on eBay from one dealer in particular. I think he was from the US but would need to check the old posts. If an actual covering of some sort was placed on the coins (beyond a polish film), I could not say, although it would not surprise me. Joe

[SVLLAIMP]

It looks like the coin is just highly polished.  As some one who quite recently had to polish family silver for a formal dinner, its not too hard to make anything look that shiny, especially something small like a coin.

[Robert_Brenchley]

Occsionally you do come across a silver coin that's been polished. I find it infuriating!

[Anachoret]

So you assume it was polished.  Do you know the method it was made? Can I hope the coin will become covered by natural patina sometime?

[bpmurphy]

Having had the coin in hand, I can say for certain the coin wasn't polished, just cleaned like 99% of all silver coins. It will tone again. Sit it somehwere exposed to the air for 6 months, it should start to get a light gray patina. Or if you're in a hurry there are numerous methods you could use to tone it yourself.

Barry Murphy

[xintaris75]

I wouldn't take for my collection one this. This seems like children's toy.
Just my opinion...

[dougsmit]

Have patience.  These days it seems many of the coins we see have been cleaned more than we might like but I have photos of a few of my coins taken in the late 1960's and today and they are looking better with a few years under their belts.  The difference I see in the two photos strikes me as mostly lighting.  It is amazing how terrible you can make a decent coin look with poor photography.  In this case the shiny coin looks to have been lighted from two sides equally and with point source lights (both bad ideas 99% of the time). 

Barry, by the way is very correct that you can speed up natural toning in several ways but one that seems to work with some safety is putting it in a bright window.  Old coin cabinets made from incorrect wood choices speeds things up, too.  I'd stop short of smearing them with sulphur in Vaseline and baking them in an oven but there are people out there in a real hurry.  I don't know what their coins will look like in 40 years.

A decade ago, I started noticing a trend among certain dealers (not CNG at the time but still a big name) favoring "naked" coins.  One suspects that most of their stock comes from new hoard material rather than old collections but I suppose they could be cleaning everything.  You control the process - Vote with your money.  Buy what you like; when enough people pay extra for toned coins, you will find more offered for sale. 

[Lloyd Taylor]

A decade ago, I started noticing a trend among certain dealers (not CNG at the time but still a big name) favoring "naked" coins.  One suspects that most of their stock comes from new hoard material rather than old collections but I suppose they could be cleaning everything.  You control the process - Vote with your money.  Buy what you like; when enough people pay extra for toned coins, you will find more offered for sale. 

I suspect the the bright shiny examples originate from recently uncovered hoards. For most collectors toning adds to the aesthetics and thus value. Therefore buying the bright shiny example may be a good investment decision...the toning that comes with a bit of time in a collection alone can give an uplift in value!

[Lloyd Taylor]

To the preceding I should add that in the last few years I have purchased a number of coins from CNG that appeared to have been recently cleaned. Within 12-18 months of purchase most of these developed a very noticeable tone that improved the overall appearance.

[gavignano]

[I suspect the the bright shiny examples originate from recently uncovered hoards. }

This is a reasonable explanation of their shineiness - in that somewhere in the process to market they were cleaned heavily. Some might like this, but I don't. I would love to see what they looked like in their pre-cleaned state - granted, they could have looked quite crudy, but I'm a fan of "less is more" with cleaning - the minute they no longer look bad,  stop. I would not buy a denarius that looked this shiny. As said, I would vote with my money. Personally, I hope this is not a trend that stays. Even if one could let it retone after many months. Whoever is out ther doing this, I humbly plead - stop.

[Lloyd Taylor]

....somewhere in the process to market they were cleaned heavily. Some might like this, but I don't. I would love to see what they looked like in their pre-cleaned state - granted, they could have looked quite crudy, but I'm a fan of "less is more" with cleaning - the minute they no longer look bad,  stop.

Virtually all the best examples of ancient Greek and Roman silver were cleaned at least once to to the extent noted.  Otherwise they would be jet black due to oxidation associated with great age, or worse through chemical build (sulphides or chlorides) up arising from interactions with the burial environment in which the hoard from which they originate spent most of its time (a couple of millennia in most instances).  So I am not sure that this is a new trend as much as a reflection of the amount of material coming to the market today from recently opened (and cleaned) hoards.... sensitive territory indeed!

[slokind]

Not knowing how to explain it, I said nothing, but I am sure that Doug (and Barry) are right.  That is, different camera chips read differently and in different kinds of light and at different distances and with different settings.  Besides, some of the new scanners read so that coins look weirdly toned.  I have had similar experiences with silver coins and have had to take them over and over to avoid either of the extremes at the head of this thread.
Pat L.

[Anachoret]

Not knowing how to explain it, I said nothing, but I am sure that Doug (and Barry) are right.  That is, different camera chips read differently and in different kinds of light and at different distances and with different settings.  Besides, some of the new scanners read so that coins look weirdly toned.  I have had similar experiences with silver coins and have had to take them over and over to avoid either of the extremes at the head of this thread.
Pat L.

It is correct, that difference of photos depends from method of filming. Lustrous image is result of scanning, not photo. But the coin is lustrous "in hand", and the scan is more realistic than photo. Also some strangeness in coin's grading given by dealer - VF. Coins in VF-condition has visible wear usually. How can this example demonstrate so shining surface, without any traces of circulation, if it was "professional cleaning" only? 
Maybe I must believe that it is "brilliant UNC"? 

[xintaris75]

Many collectors haven't possibility for return a coin, if they are not like this. As example, if you want send back a coin from Greece, you must to take a permit for export - it's really pain and at 90% cases you take refusal from authorities.
Same situation have and collectors from Russia, Bulgaria, Turkey etc... 
How they can "vote with a money"

[Anachoret]

Have patience.  These days it seems many of the coins we see have been cleaned more than we might like but I have photos of a few of my coins taken in the late 1960's and today and they are looking better with a few years under their belts. 
Barry, by the way is very correct that you can speed up natural toning in several ways but one that seems to work with some safety is putting it in a bright window.  Old coin cabinets made from incorrect wood choices speeds things up, too. 

Let me ask:
1. What kind of wood is capable to accelerate natural toning?
2. How correctly keep coins in contact with wood?
3. Does any correlation between wood's kind and color of patina exists?
4. How are forming such pleasant blue and golden colors on silver, for example?

[Numerianus]

It might be that I am not in the theme... I read somewhere that the practice to make a copy of the coin before selling is
more and more frequent in some counties. A collector who did not believe in this investigated his coins under microscope and noticed
on them some stuff (like rubber or silicone) used for copying. Of course, professionally cleaned EF specimens suit better
for such a procedure. Could this explain the phenomenon? 

[Pseudolous]

For what its worth - most of the "blue" I have seen on coins I have purchased, such as the example below, do NOT reflect what the coin looks like in the flesh at all. Instead, somebody playing with the "level equalization" tool in a photo- editing program. The image below has even been lightened to remove the bluish cast that was more pronounced on the seller's original image.

I still like the coin but do not like the habit of certain seller to play with their images!

[bpmurphy]

The bluish color probably isn't the result of someone playing with the image, more than likely it's a white balance problem that most non-photographers don't understand nor do they know how to correct it. Most sellers don't know enough about photography or Photoshop to even begin to play with their images, let alone play with them in a way to make the images look better. You also have to take into consideration that not everyone's monitor is calibrated the same way, so what looks really blue on one screen may be less blue on another and maybe greenish on yet another.

Barry Murphy

[cryptofenix]

Gents,

I'd rather disagree that toning process after that sort of "cleaning" or "covering" comes across very easy. I bought this  Aug denarius 4 months ago and tried to get rid of that nasty shinning as well as recapture part of the natural toning. However, it was more cumbersome than I thought and I haven't advanced much. The coin still bears an impression of being treated with some preservative after cleaning. Please mind that I have no doubts in its authenticity.

[Robert_Brenchley]

Four months isn't long. Give it a couple of years, and then compare it to the current image.

[xintaris75]

Something is wrong: dealers (or diggers) for some reason, cleaning a coin to a mirror shine, knowing that after that mode of cleaning the coins go down in value?

[napki]

Chemical cleaned make silver very white and bright but will re-tone eventually, maybe few months, maybe many years. Natural texture of surface usually not very affected. On other hand, abrasively polished silver which reflect like mirror will also develop the toning over time but will always still reflect like mirror, so ruined.

[Lloyd Taylor]

Something is wrong: dealers (or diggers) for some reason, cleaning a coin to a mirror shine, knowing that after that mode of cleaning the coins go down in value?

Its a trade off between volume moved rapidly to market and quality of tone which requires careful, skillful cleaning.  In the end volume moved to market wins hands down!  The expedient way in the cleaning process is to dip the roughly cleaned silver coin in Silver Dip or some similar product aimed at the jewelery cleaning market.  Quick and simple but it leaves a bright shiny finish. It also has the advantage for the finder/looter/original seller of removing all traceable material that may reflect on location and thus ownership of the hoard from which a coin originates, greatly reducing the risk of legal challenge under portable antiquities law and facilitating the path to market.

[xintaris75]

There are three problems:
First, this cleaning mode destroys the signs of authenticity
Second, after such a cleaning on the coin will not lieth normal patina
and third, after such a cleaning coin looks like Christmas-tree
Because this cleaning mode seriously damage a coin's surface, it is not fair to sell these coins without written description the features of the cleaning, the more manipulated with images to disguise unnatural shine. So, it must be written at description "sunshine cleaning" or "mirror cleaning" or "polished" or...