Error Other | 1973-D Kennedy Half Dollar--What Is This?

[papascoins]

Hello all,

First of all, I know this is not a Lincoln Cent Coin, but I wanted the experts on here to see this.
I'm trying to figure out why it looks like there's a "halo" around the image of this Half Dollar. It almost has a 'dirty' effect, (a low luster area), maybe because of the surface's texture. I took the photos in low light so you could actually see the 'halo effect' better. I took some close-ups trying to see if my theory of "abrasion" would hold up. I thought maybe it had something to do with Die Deterioration, or something about the die metal flow.
I'm sure you all have seen this 'halo' effect on early 1970's Kennedys. I would appreciate any opinions on this coin.

Thanks!

[mustbebob]

Based on those flow lines, I would say this is deterioration as you suspect.

[Petespockets55]

I agree with Bob.

Those are pretty heavy die flow lines.

[jfines69]

Die deterioration causes that effect... It is spalling of the die thru continuos high speed/pressure impact... Much the same as we see when a rifle bullet hits a steel plate... Here's a youtube clip that shows spalling https://www.youtube.com/watch?v=iFpjxC1I9VI Hope that helps