2008 Lincoln cent strange marks

Are you asking about the vertical lines on the obverse face?  

Yes I am and the one by his ear 

I can't see anything in those pictures by the ear but the vertical lines are fairly common on the copper plated zinc coins.  It is the result of the copper plating process. You'll find many like that.

See more pictures here: https://en.numista.com/forum/topic144448.html

Horizontal on this fella

Nice example!

An interesting topic to research.  Here is an article:

https://www.coinworld.com/news/us-coins/different-causes-of-stripes-on-coins-are-not-fully-understood.html

And this is pretty fascinating too:

https://www.traildies.com/lincoln-cent-trail-dies-for-2000-to-2009/

Thanks for the links.

This particular type of lines (parallel covering the entire face) is unique to the copper electroplated zinc coins. I haven't found an explanation as to exactly what causes it but I haven't looked too hard for one.  I've never seen them on pre-1982 pennies.  I suspect they're related to the grain structure of the rolled zinc sheet but that's just speculation on my part.

 I wonder if that is what going on with this dime

Nice read in the links 

ALLRED1950

 I wonder if that is what going on with this dime

 

 

Not the same but I believe related. The pennies look like that fresh from the mint. The dime, not being electroplated but clad (similar to the quarter) only has that appearance after some environmental exposure. I've seen the same on dimes and quarters left in a vinegar/ salt solution for a long time.  The etchant brings out the grain structure of the material (elongated grains oriented in the sheet rolling direction like the pennies).

So, coincidentally, I was looking at some aluminum foil under the microscope at the lab this morning (troubleshooting, looking for contamination, long story) and I saw the same lines.  I believe the metal rolling theory has just gotten some more evidence.

I suspect that the electroplating piles up along these lines and makes them more macroscopic.

Here is a representative picture at 60x of what I saw: I just Googled it as taking a microscope picture with my phone is a pain in the ass.

I have a Danish 50 øre that has stripes, I’ll send a picture when I get the chance

An example of what I was discussing above. This coin still had some mint luster when I started.  Same coin, different lighting.

rsirian1

An example of what I was discussing above. This coin still had some mint luster when I started.  Same coin, different lighting.

 

                                    

My 50 øre coins looks something like this, but there’s some parts of the stripes that are the color of fresh copper, while most of the coin is the color of weathered copper