I'm trying to create a wormhole effect for a render.  I'm playing with the half torus prop object that comes with C8 (but I'd rather just be able to half of it, but those formulas are wacky).  I've tried all sorts of combinations of glass, fire, exotic glasses, etc... but can't seem to get it even close.  I want it to look a little like the vortex from the old "Sliders" TV show... transparent, but turbulent with a high but changing refraction.

Any help would be greatly appreciated.