2006 D Colorado Quarter Struck Through Plastic?

It maybe glue and gunk in the glue on the surface of the coin? But I have found one that looked a bit like yours that had the fiber still attached to the coin :

Probably most likely glue.

I'm somewhat confused as to what kind of glue is being referred to. PMD glue or struck through glue. I've seen this before and know what is underneath. For some strange reason I removed this glue or plastic from this New York and lost the retained piece. You can see the strike through underneath

Denver switched from the vertical strike Bliss presses to the horizontal strike Schuler presses in 2005. I would think that struck-through errors would be less common in a horizontal-strike environment.

One post-strike (but still in-mint) possibility could be either the gripping arm or the sealer on the bulk bag crimping machine. That said, I do not see rim damage on this coin, which I would expect from the bulk sealer. My inclination is that the damage on this coin this is both post-strike and post-mint. The generally circular nature of the damage and the location in the center of the coin suggests damage from a coin roll crimping machine.

Thanks fortcollins. I see what you say may be coin roll damage but that doesn't explain the majority of the issues imo. Look at all the incuse areas. Look at liberty. No coin roll damage there

I'm with @e&v on this one. Your quarter has dried glue on the surface--something most likely like crazy glue. Sorry but it isn't struck through and it isn't a mint error.