Is this shadow effect caused by faulty die polishing?

CalGold

Here are two details from two different 1882-s Morgans showing almost identical shadowing around the date and stars. Detail 1 is of a high grade (MS 67) frosty coin. Detail 2 is a PL coin. The date on the PL appears to be recut with signs of doubling in the first 8 and appearance of a vestiage from a previous cut of the 1. Note also the "white" area near the point of the bust on each coin.









CG

nwcs

It's from metal flow as the metal is rushing towards the outside edge.

CalGold

Thanks Neil. Does everyone agree?

CG

JadeRareCoin

CG, it looks like a classic example "pull away" toning to me, which can only occur with time......lots of time. There's a possibility that the toning is the by-product of an improperly rinsed dipped coin, but hard to tell from an image. It is my opinion that you are not seeing faulty die polishing.

fivecents

JadeRarecoin....

CalGold

Jade,

I am familiar with shadow toning that is common around the date, but I do not see how there can be pull away toning on two white coins. The shadow effect and the white area on the point of the trunk of the neck are almost identical on two different coins. That is why it seems that these may have been struck from the same die and that the affect relates back to the die.

CG

Rob790

It's metal flow that is under excessive pressure, enough pressure to change the metallic structure to so that the 'pulled away' metal becomes more resistant to toning. This cause the "pull away" toning commonly seen on many morgans and other various denominations.

See this
related article.

It has nothing to do with die polish, they are basically stretch marks caused by the die onto the planchet.

prooflike

Rob is correct, it is a result of an area that has become more resistant to tarnishing.

If you were to mega-dip the coin, you probably wouldn't notice it, except maybe under 30x if you knew what you were looking for.

CalGold

Interesting. I do not think of white coins as being "toned" but upon relfection there is an element of oxidation/sulphurization even on white coins. I was thinking it was a die polish issue because of the similar white mark on the bust point and because some DMPL CC Morgans are famous for a "halo" affect around the central devices that I believe is usually attributed to die polising.

CG

fivecents

From what I understand shadowing has nothing to do with metal flow. Gsaguy once explained to me that shadowing occurs when molecules fall over the coin causing toning(no joke). The shadowing occurs where the surface of the coin is protected from the raised date or devices from contact with these molecules. The only way this can happen is if the coin sits undisturbed and in the same postion for a VERY long time. Gsaguy used a coin sitting in a canvas mint bag in the US Treasury vault as an example. He told me to imagine the molecules falling down from the canvas bag and flowing over the coins with time causing the shadowing. That is why it always looks like a shadow. A real shadow works the same way only with light instead of toning.

BTW where is gsaguy

Rob790

It's metal flow. All you need to do is examine the area under 40x magnification and it becomes obvious that it is metal flow.

If it were to occur as you described fivecents. the 'shadow' would not occur radially as is ALWAYS seen. It would either occur all around the devices (not on just one side of the star in this case but all around it) or in one uniform direction on all the devices (like a real shadow), not radially from the center. On the small molecular scale you are describing, molecules do not fall like dust- on that scale, molecules move in relatively random motion due to heat and other quantum mechanical effects. And this can also occur on AT coins, which by most definitions occur within a short time frame.

nwcs

And this is yet another reason why the appearance or not of toning around the stars is NOT an indication of AT or natural toning.