the le aleady contains some basic explanations
go to the scripting window and you’ll find some doc there
this diamonds are sort of faking light dispersion which cannot be done right now in cycles!
These diamonds have materials attached that fake the dispersion of diamond, so that colours separate as they pass through. This is done with material nodes in cycles.
now don’t forget here that the light set up is done for a very dark scene to emphesize the colors from the diamonds
this may not work well if you increase the light intensity!
hope it helps