Distinguishing Roller Marks from Die Polish Lines

A light chemical cleaning of a Morgan dollar revealed countless parallel lines across its entire surface, which had been hidden by toning.

According to a poster in an online collector community, the coin had been assessed as "MS, Questionable Color." The poster noticed the lines after removing most of the toning. The lines cross uniformly over both the coin’s fields and its devices, such as the portrait.

The poster theorized these were "roller marks" originating from the planchet before the strike. Roller marks are parallel lines created when a silver ingot is rolled into a strip of the correct thickness for coin blanks.

Other participants suggested the possibility of "die polish lines," which are created when a die is polished. However, die polish lines are generally thought to stop before they reach a device.

Crossing the Device or Stopping Before It?

In the discussion, whether the lines crossed over the devices emerged as a key point for distinguishing roller marks from die polish lines.

One participant shared a photo of an 1879-S Morgan dollar graded MS64 by NGC. The coin's reverse showed prominent lines, but it was difficult to determine from the photo if they crossed over the eagle device.

An opinion was also offered that many Prooflike (P/L) Morgan dollars from 1921 have prominent lines.

Ultimately, the thread did not reach a conclusion about the lines on the original poster's coin. The case demonstrated the difficulty in determining whether surface lines originate from the planchet or the die, and it highlighted a key point of observation for making that judgment.

No clear photograph showing the lines on the poster's coin was ever submitted to the thread.