1971 reverse error?

[Peter]

Will, perhaps we can add "rippled" to the list? Would the OP mind if we used this image as an example if Will agrees?

[mikediamond]

I'm not sure how it's done. Traditionally it was believed the effect was achieved with a rotating wire brush. I have my doubts, as I never see any scratches. But these alterations are common and they can get quite severe. Rippled coins (at least the less severe examples) can resemble die deterioration and coins struck through rotated, late-stage die caps and rotated split or rolled-thin planchets.

[mikediamond]

Here's a more severe case of rippling: http://www.ebay.com/itm/191514773572

[jallengomez]

I have a half-baked theory about these that I'm still ironing out. Any solid state physicists around here? We know from acid dating Buffalo nickels that the planchets retain a sort of "memory" of the strike which can be exposed with acid. Could it be that the shock waves or flow waves created during the strike(and which are normally invisible) could be revealed with acid. This could perhaps take on a different look depending upon the composition of the planchet and/or the force used in the strike. In the case of certain composition such as the Lincoln example, these waves could even mimic the devices. Perhaps as the metal flows into the device and then rebounds into the oncoming metal flow? Similar to the crest created with an outgoing wave. Again, this theory is still in the "could it possibly happen" stages.

[jfines69]

I have a half-baked theory about these that I'm still ironing out. Any solid state physicists around here? We know from acid dating Buffalo nickels that the planchets retain a sort of "memory" of the strike which can be exposed with acid. Could it be that the shock waves or flow waves created during the strike(and which are normally invisible) could be revealed with acid. This could perhaps take on a different look depending upon the composition of the planchet and/or the force used in the strike. In the case of certain composition such as the Lincoln example, these waves could even mimic the devices. Perhaps as the metal flows into the device and then rebounds into the oncoming metal flow? Similar to the crest created with an outgoing wave. Again, this theory is still in the "could it possibly happen" stages.

Very interesting theory... Be careful with the hot iron tho

[jallengomez]

Very interesting theory... Be careful with the hot iron tho

And my mixed metaphors!

[willbrooks]

I have a half-baked theory about these that I'm still ironing out. Any solid state physicists around here? We know from acid dating Buffalo nickels that the planchets retain a sort of "memory" of the strike which can be exposed with acid. Could it be that the shock waves or flow waves created during the strike(and which are normally invisible) could be revealed with acid. This could perhaps take on a different look depending upon the composition of the planchet and/or the force used in the strike. In the case of certain composition such as the Lincoln example, these waves could even mimic the devices. Perhaps as the metal flows into the device and then rebounds into the oncoming metal flow? Similar to the crest created with an outgoing wave. Again, this theory is still in the "could it possibly happen" stages.

Maybe Thad will do some experimenting for us. He surely has access to the good acids. Send him a PM, Jody.