1877 Zs (Zacatecas) 8 Reales

When I see what I think are adjustment marks on one side, I actually like to see strike weakness on the other as confirmation. I suppose some people would avoid this sort of thing, but to me it makes for an interesting coin.

Zacatecas was a high volume mint during most of its operating life and in particular the 1870s were plagued by weak strikes. That is the case here. The marks on the cap appear to have been there before the planchet was struck.

I actually see only a few actual adjustment marks on the surface. There are three sets. Adjustments were common in the very early days of the mintage but were less common during the period when power equipment proliferated. Adjustment marks are filing marks - they are parallel over the width of the file itself and they tend to be irregular in depth and orientation often crossing one over the other. There are the non-parallel deeper scratches that cross the cap at several (3) different angles of incidence. (see picture below the RED lines). Some of the adjustment marks appear to curve slightly. People familiar with flat filing will notice the curve which tends to bend toward the strong side of the person doing the filing.

Most of the very uniform parallel lines seem to be caused in the rolling and lamination procedures. These are uniorm in depth over their entire length. These are the lines at a high angle of incidence relative to the bottom of the cap (dark blue lines). Those were not caused by hand filing of the surface of the blank in my opinion. They are too uniform in in depth (of each notch) and parallel over the entire surface left unstruck by the dies. I see that as extremely unlikely to have been due to hand filing. It is far more likely that they are either due to marks on the rollers that produced the strip of metal for blanking or even more likely still that they were caused by damage to the surface of the lamination die itself. They are like drag marks caused by a chipped lamination die. I hope that is clear. I have seen this feature on too many 1870s Zs coins for it to be the result of random filing.

Here is a sketch. The red groups are individual filing strokes made AFTER the coin blank was laminated. The blue lines show the extent of the parallel grooves caused by the production and finishing of the fillet strip.

The only caution I forgot to mention was that you would need coin in hand to make sure the "red" scratches were on the planchet BEFORE the strike. Near the ends there should be faint indications of compression of the grooves by the strike pressure. That is next to impossible to be sure of in a photo and in this case I could not actually see anything that I would trust as a compressed image - except for some of the lamination marks.

I also noted that this appears on many Zs issues of the 1870s and I came to the conclusion that the vast majority were lamination marks years ago. I suppose if you compared a few dozen side by side it would be possible to match up the damage like tree rings used in dendrochronology.

It has the look of damage from lamination - in my opinion.

Edge filing does not work on blanks that will be edged in a two die edger (casting machine). It would cause slippage and delay the process.