1993D doubling?

[ericodapro]

The tops of the columns look knobby and the left edge of the memorial looks doubled? I saw similar looking doubling on CC but not on same column. Any input?

http://i12.photobucket.com/albums/a232/Sin_More/1993ddr.jpg

http://i12.photobucket.com/albums/a232/Sin_More/1993dg.jpg

http://i12.photobucket.com/albums/a232/Sin_More/1993do.jpg

http://i12.photobucket.com/albums/a232/Sin_More/1993dx.jpg

http://i12.photobucket.com/albums/a232/Sin_More/1993dp.jpg

[JeanK]

Hi Eric,

I believe what you are seeing on all outer edges of the building, as well as around the figure of Lincoln are plating separations caused by the zinc inner core and copper outer shell of the coin not bonding properly. This is also the reason for the bubbly surface of coins minted from mid-1982 to the present. The mint switched from the bronze (what we call copper) metal composition to the zinc/copper core with a plating of copper and there have been problems with the coins since then.

Not having the coin in hand it is rather difficult to be absolutely certain, but the 'doubling' on the devices of the obverse and reverse of the coin appear to be caused by the same plating problems, which gives the 'doubling' appearance of all the devices on the coin. If my eyes are not deceiving me, I think I see a little bit of die clashing on some areas of the reverse. Maybe on the lower left end of the memorial and possibly between a couple of columns.

This is a rather nice looking Lincoln for the year, but it would be wise to consider the storage problem it might present due to the exposed zinc core, such as you see around the mint mark. This is a spot where deterioration can take over and ruin the coin for collecting purposes.

If I am not correct about this I know our experts will pop in and let me know about it.
I will let them have the final word.

Jean

[jcuve]

Nice analysis Jean! I am not an expert but I think I agree with you that it is a plating issue. From the pictures I see plating problems all over as Jean noted. I may not be seeing it correctly, but it looks like the ghost like doubling appears on both sides of the memorial too.

Hopefully one the experts will chime in. If not, try PM'ing...

Jason