by Fluxx
At end of round skills are refreshed so you could saya) as you refresh your skill it isn't in the middle any more so you don't get your crystal
or
b) as your skill isn't in your skill offer it doesn't refresh so you get your crystal at start of next turn and flip your skill so you can't use it again this round.
Both interpretations make sense for me. I haven't checked the rulebook for the exact wording so I don't know which I would say is correct.