Help Identifying the error #1

[EgCollector]

I know nothing about errors, and i have been into US coin collecting lately.
I found some coins with errors (according to my openion) that i hope someone could help about;

Is this an error?
What is the error name?
Does this increase the coin value?

Thanks for your help 

[EgCollector]

The D mint mark is filled/solid and not clear/empty

[EgCollector]

[EgCollector]

[EgCollector]

[EgCollector]

[Nighthawk]

Amr, I think what you have is a common occurence, not really an error, although I am not an expert on errors. There was obviously some dirt or gunk build-up on the die when it struck the coins, thus creating a filled mint mark. Again, I believe this is a common problem on U.S. coins, but I would ask for a 2nd opinion! 

[EgCollector]

Thanks Nighthawk for the info. Hope that another member confirm your opinion or have another 

[Yass]

I have a number of these that have found their way to Oz.  If I can find them here, I can only assume that it is a common occurrence.

[EgCollector]

Thanks Yass 
So, you and Nighthawk say that it is a common occurrence.
Does this mean that it is an error that commonly occur, thus it is of no importance.
Or it is not identified as an error by any means. 

Thanks 

[Nevol]

I also have a few with partially filled 'D's", 1975, 76 & 80.  Later years seem to have a more 'open' or larger 'D' Mint Mark.

[EgCollector]

Amr; here is a definition of what an Error is:

Error:
A coin, token, medal or paper money item evidencing a mistake made in its manufacture.

If you go with this definition, then you have to ask yourself, it the so called error was a mistake, or just something they didn't think was serious enough to warrent shutting down the presses. I happen to think they knew the dies were clogged, but didn't figure it was worth loosing press time to clean up. So I guess what I'm saying it it will depend on what YOU think it is.

Thanks OldDan, This was wise and informative 

[buda]

it is a error but not a rare one

[EgCollector]

Thanks buda 

[longnine009]

Clogged dies are very common. Typically metal from thousands of planchets have little bits of metal  scraped from them when they are struck and those  particles fill in the crevices of the die. 

But I believe you have die chips and not clogged dies. Clogged dies would not show any mint mark at all or would show only a partial mint mark. Chips happen because the area inside the mint mark is a weak point in the die. The mint mark is hubbed (cut into) the die. You could say that the inside of the mint mark does not have any metal around it  to "brace it" from the shock of striking, so they break off leaving a hole in that spot which will transfer as a raised spot on the coin.  At least that's how it looks to me.  Chips are very common though. Remember dies are backwards from coins. What's raised on a coin is recessed in the dies.

Lincoln cents struck in the 50's used to have chips in the R of Liberty Especially the lower part of the R and they were called a "Skirted R." . Sometimes just half the of the bottom part of the R would be chipped and it was called a Mini-Skirt.