2006 d penny 0

[Tridmn]

Not sure what is going on. If this is mint damage or after. Need help please.

[Tridmn]

[Tridmn]

Also only weighs 2.46 g

[l.cutler]

Looks like some foreign substance on the coin. Weight is normal, well within tolerance.   Can you post pictures of the whole coin?

[Greenstang]

Possibly glue but as stated, will need a full picture.

[James_OldeTowne]

It also might be a planchet lamination.

[Tridmn]

Also only weighs 2.46 g

[Tridmn]

Reverse 

[Tridmn]

Best pics I could get

[l.cutler]

I would say something spilled on it, weight is ok.  

[Greenstang]

Still looks like glue to me. The fact that you can see through means it is something transparent. A soaking in acetone would probably get rid of it.