Amel to Lav het Amel?
You would get 50% normals het amel and lav and 50% Amels het lavender (if there are no hidden hets).
Opal to Amel?
IF an opal is an amel lavender, than you would get 100% Amels het lavender (if there are no hidden hets). I haven't heard if anyone has as yet proven opal to be an amel lavender or not...JY, Clint, Rich, help?...but I think that is the belief right now.
Corrections welcome, jmho.
***Editing after the fact***
Oh yeah, Pearl is the one we aren't sure of, opal is the coined name for amel lav's. That's right. LOL. Unfortunately, to me, opals and pearls are catergorized as the same thing in my little brain (speaking of the mineral version, of course) even though I know they aren't the same thing).