is this a duck or chicken egg!!

[Cencor]

Hi i posted this in the egg forum earlier but had no replys we have 9mixed orpingtons that lay light.brown eggs a mallard duck who lays two green eggs a day. In the last few days qeve been getting these white eggs, as big as a duck egg an feel really smooth (like a duck egg). There not opaque. The thimg is we have two more ducks in with the mallard an orpis ! 2BO drakes they both have curls. So are we wrong or is a chicken reslponsible. Oh an we cant tell from the.laying as even the mallard lays her eggs in the nesting box.
Thanks everyone

 

[Cencor]

 

[Lady of McCamley]

The colors in my monitor show that as more of a light tan egg which would be typical of a Buff Orpington.

I can't account for the smoothness of the egg, although sometimes mine are pretty smooth.

Unless you've got a duck you can account for...I would suspicion one of the Buff Orps.
Lady of McCamley

 

[Cencor]

The light tan are the buffs but middle eggs are definatley white abright white. I think what i wanted to know is can a sex feather be wrong