It fell back with a satisfying "thunk."

I have stainless steel sinks, so I concluded that my toss had brought the ice cube down one vertical side and thru the curvature at the bottom with enough speed to go across the bottom and up the other side.  Hmmm? again.

I retrieved the ice cube and tried the toss again.  Nope.  Tried it again.  Nope.

It occurred to me that I could probably try that all day (or, given my age, all my life) and not repeat the precise alignment required to make that happen again, so I gave it up and decided to get on with my day.

But carefully.   There may be some peculiar stuff goin' on in the universe. :-)

Take care,

Russ