Which of 3 breeds laid this egg?

[Ebz5003]

I have been trying to catch which hen has been laying this egg each day, but haven't figured it out yet! I realize there are differences even within 1 breed, but wondered if anyone could tell which breed could have laid this: Barred Rock, Sapphire Gem, or Rhode Island Red? They are all 18 weeks old and I've seen this mystery egg for 2days now.

 

[aart]

Have you had other eggs too?
Could probably be any one of those three breeds.
Might have to actually see it come out to know for sure.

 

[Ridgerunner]

Check out this link

Who is laying what egg? - YouTube