Calling on error experts. Strike through?

dlmtorts

Several years ago I purchased an uncirculated roll of 1958 quarters. Several of the quarters, about 10-15 of them, had an area to the left of Washington’s head, in the field, with a concave shape. The shape was slightly different on each quarter. At the time, I believed it was something stuck to the obverse die that changed shape with each strike. I put them away and forgot about them and I am not sure where most of them are store now. However, I did come across a couple of them today. They are hard to image but I gave it my best shot. Is this a strike through error? If so, how did it happen, given the history? Thanks for looking

silviosi

What show the reverse?

BustHalfBrian

It does appear to be a struck through something

dlmtorts

Here are pics of the reverse.

And here is another coin from the same original roll with a strike through in the same area. Again, it is concave. Hard to show that in my images.

Clackamas1

My gut says no, y0u should not have a raised rim into the fields.

ifthevamzarockin

Struck through grease.

MedalCollector

Yes, a small strike through would be correct! Typical appearance for a small bit of mint “grease”.

ricko

It does appear to be a strike through.... grease or retained crud on the die... Cheers, RickO