Opalized Kerr jar?

[Humabdos]

I know most Kerr jars aren't worth much but the second from left on the top seems to be opalized (sp) None of my other jars have this effect. Would this make it more valuable or is it commonly found?

 

[woody]

From what I can see from the picture that color is called "cornflower blue".
If that is the color the bottle is worth more because of it.