Can someone explain to me or point me to a resource that explains how to identify adjustment marks and distinguish them from scratches? I understand what they are and their purpose, but I haven't been able to visually see a difference between them and scratches? This half dime is a great example, it just looks like some bad scratches to me. https://www.coinworld.com/news/precious-metals/heavy-adjustment-marks-can-shave-market-value.html
Scratches, even when mostly straight, usually follow a more random zigzag or crooked pattern, where as adjustment marks (which were made with a file, I believe) are almost always a series of parallel lines. Also, since the filing was done before the strike, you can often tell that by examining the lines closely. The edges of a scratch are like a raw wound in the metal. Adjustment marks which have then been subjected to the pressure of dies and struck over, tend to be more "squished out" and less jagged as a result. The edges of the "scratch" will be softer looking.
Short summary- once you've seen 'em, you'll know 'em. First time I encountered them was on a dollar sized coin: a 1766 French silver ecu. The good news is, I've never seen a case as severe as that 1795 half dime in the article.
An examination of the mark using a stereo microscope and florescent light (unfortunately not available to most) is all you need. One thing I'll add to the explanation above is an adjustment mark tends to weaken at both ends until it disappears due to the strike. On untoned coins in high grade, you can see the original, unstruck planchet metal INSIDE the adjustment mark. Scratches look different.
