This is an ebay ad, and I don't believe that it is "pocket worn". This is a fairly recent knife (Q-DFC stamp), and that doesn't look like normal wear to me. Do you think it is from heat or a chemical? Whatever it is, it seems to be on both sides. Maybe this is the Incredible Hulk's pocket knife?? https://www.ebay.com/itm/Queen-Cutlery- ... 2747712317
"The Luggage had a straightforward way of dealing with things between it and its intended destination: it ignored them." -Terry Pratchett
You can buff Delrin and plastics but you need a string wheel not a layered cloth or muslin wheel because of the heat buildup. A string wheel creates less heat and allows the heat that it creates to dissipate very quickly. I think that knife fell victim to a cloth or muslin wheel and someone who wasn't paying attention to what they were doing.
If y'all look real close, both sides of "wear" on the knife are almost identical. A consistent over-buffer, maybe. What pattern is it supposed to be, it looks like a #49 but the length is not correct for that pattern but hey, what is an 1/8" among friends? Treefarmer
A GUN IN THE HAND IS BETTER THAN A COP ON THE PHONE.
I had a Schlieper (German Eye) small canoe knife with black synthetic handles in my vehicle console. One day I noticed it had "melted" areas on both sides of the handle. Never did find out what it came in contact with.
This is what happens to synthetic black handles when you try to grind the head off the spring rivet to replace a broken spring. The pile side got put out quickly;the mark side went up very fast and filled my shop with smoke. Very difficult to extinguish.