Egg color: What breed is laying this?

[KGBYB]

Trying to see of the frosty color on the bottom of this egg is breed-specific, or just perhaps some calcium dust?

 

[3riverschick]

It just happens sometimes with brown eggs
nothing worry about
could be any brown egg laying breed lays an egg like that
it's just an occasional occurrence ,nothing big.
Karen

 

[KGBYB]

It just happens sometimes with brown eggs
nothing worry about
could be any brown egg laying breed lays an egg like that
it's just an occasional occurrence ,nothing big.
Karen

Oh, I thought maybe it was breed specific. Is it just calcium?