It is the part that probably the most annoying one of the game, imho.
I am not sure that there is a certain way to obtain the crystal, but i obtained it 3 times with different characters. In all of them i backflipped and ready m'finger on SHIFT. Becuase of ceiling is a semi-sphere, If you jump correctly, you stuck into ceiling revolving (sp/?) and you will have enough time to grip it.
Patience
