Could coins be graded by metal flow?

MrEureka

The surface of every struck coin exhibits metal flow over 100% of its surfaces. Under a microscope, it should be easy to detect disruptions in the metal flow caused my wear, scratches, dipping, etc. It shouldn't be all that complicated to analyze the surfaces of a coin and calculate an OBJECTIVE grade.

It's obvious to me that this will be done sooner or later. The question is, why hasn't it been done already?

ms70

Too time consuming? I believe there has been past experiments with computer grading.

clackamas

They already are, except that the human eye/brain does it.

Cam40

that is a huge element in grading no doubt but there are other elements to consider.
strength of strike and how it relates to the series/date.
quality of the dies and planchets plays a good part of it too.
and what level of die state should play a part in the grading of a coin?
can a late die state coin grade better than 64?
or a slightly weak strike always be a 64 at best?
grading is tough when you have so many variables
to be aware of.
nearly any coin can be talked up or down in grade points
with seemimgly logical reasoning either one way or the other.
its almost never cut and dry.

ER

Yeah, but when you get to eye appeal, it becomes subjective.

Cam40

ah yes. toning
cant forget that demon.

mr3holesinone

Didn't PCGS have a program years ago to grade Morgan dollars? I thought they were going to experiment with Morgans since that was the coin most graded at the time. I remember that they had trouble trying to get the program to recognize eye appeal. Strike, whizzing, cleaning, marks and circulation wear would seem to be the easy part.

Cam40

the computer they had come up with some years ago was called `the expert`
not sure they play with it anymore,or will admit to using it.
maybe when they get tired of grading statehood quarters
all day they fire that program up and go drink a beer while they count
their monies.

Lakesammman

Andy:

So a darkly toned, ugly, bagmarked coin with edge dings but intact flow lines would be a gem?? The flow lines would be a component of originality but not a overriding issue.

MrEureka

So a darkly toned, ugly, bagmarked coin with edge dings but intact flow lines would be a gem??

No. Dark toning and edge dings damage metal flow.

As for strike, eye appeal, cameo, die state, etc, all of those things can be easily assessed from an image. I don't see much benefit in assigning a numeric value to those subjective aspects to a coin. Better to quantify the things that cannot be seen as easily in an image and let people figure the rest out for themselves. Of course, that would not preclude a TPG from offering an objective technical grade based on metal flow analysis AND a separate opinion as to a subjective grade. Let the market sort it out.

I find it interesting to consider how various forms of coin doctoring might be interpreted by a computer that analyzes metal flow, since doctoring often damages (and sometimes completely obliterates) metal flow.

Lakesammman

I see what your saying...good idea. Especially for high end proof gold coins. Would have to be computer generated, o/w the graders would have to spend more than 10 seconds with the coin.

oreville

<<<<<<<<As for strike, eye appeal, cameo, die state, etc, all of those things can be easily assessed from an image. I don't see much benefit in assigning a numeric value to those subjective aspects to a coin. Better to quantify the things that cannot be seen as easily in an image and let people figure the rest out for themselves. Of course, that would not preclude a TPG from offering an objective technical grade based on metal flow analysis AND a separate opinion as to a subjective grade. Let the market sort it out.>>>>

Agreed with the above. Except that with strike and cameo/deep cameo the use of them as an adjective only splintered the grades with adjectives such as FBL, FB, FH, DCAM, CAM, DMPL, PL, etc. which created greater complexity in the numerical grade charts.




<<<<<<<<No. Dark toning and edge dings damage metal flow. >>>>>>>>

Problem is (1) NGC slabs do not always reveal edge dings, (2) when does medium pleasant toning become dark toning? Becomes a bit subjective as well? (3) Edge dings are often not in the midst of metal flow lines.

morgannut2

Yep, even dipping is easily detected microscopically. The problem is part of the coin has to be coated with gold to generate good electron microscopic images. There is no data on gold though that I'm aware of currently. It would be interesting to find out how many supposed original rarities have actually been dipped!!