Unusual Morgan Silver Dollar Error -- your explaination?

tincup

Ran across this neat Morgan Silver dollar error coin. I can come up with a theory on what I think happened to cause this, but would like to get some others' input. As an over view, since my photos may not show the effect very well: There is a prominent elevated ridge (like a mountain range) that runs from the date, over to the rim at around 4 o'clock. Below this ridge... in the stars and the 1 in the date... are elevated bars going across the device. Also, between the stars, and between a star and the 1 in the date, is a line; in one place it appears to be braided and multiple stranded or twisted. This appears to be elevated also from the field. I do not believe this to be post mint damage... but what say you? A good error? Or not worth only bullion?

BustHalfBrian

Some sort of planchet flaw pre-strike? Like a retained lamination.

CaptHenway

Appears to be a planchet flaw running under the surface that is starting to separate from the rest of the coin. Such an error is commonly called a lamination error, or in metalurgical terms a de-lamination.

grip

Anything on the reverse?

tincup

Planchet flaw does seem to be a possibility for the ridge... especially since there appears to be some indication of a lamination on the rim at 4'oclock.

But still would not seem to fit for the areas of the stars with the raised areas... perhaps a different error mechanism? Only thing I can think of is perhaps a strike on some wire or something, causing damage to the die... which would then be transferred to the next strike?

tincup

Reverse is completely normal as far as I can tell. Weight of coin is 26.76 grams.

FredWeinberg

The Captain is right - all I can add is that
in purer terms, it can also be called an
'occluded gas bubble'

It's a pre-laminated planchet in that the
improper metal mixture which causes
the flaked lamination on the surface is,
at this point, a raised bubble.

If it circulated another year or two maybe,
it could have turned into a lamination that
we normally see.

BLUEJAYWAY

I can't be definitive on the cause so I will defer to Tom/Fred. The occluded gas angle reminds me of my 1947 Lincoln in my lamination Lincoln date/MM set. It has the occluded gas bubble in the date area. Found it in 1971 and sent it off to CW/Ed Fleischmann to verify. He stated someday it may split/pop. Still has not done either. Only one I ever found.

GeorgeKellogg

I am going to propose an alternate theory.

It could be that the die suffered damage, such as severe rusting, on its lower area, which was subsequently removed with a grinding or polishing wheel. This resulted in a localized area where the field was lower than the field on the remainder of the die. On the struck coin, this area of the field would appear higher than on the rest of the coin. There also appears to be elevated bumps in this elevated area of the field, which may be remnants of rust pits on the die. The elevated area also appears to be weakly struck, compared to the rest of the obverse.

It would be interesting to examine the corresponding area of the reverse to see if there is any striking weakness.

tincup

The reverse side does not have any weakness. Sounds like occluded gas bubble is the most likely explanation for the raised ridge area.

Many thanks for the input!