It's from MFFS (Modular Force Field System) mod
It macerates into Forcium, which is used extensively in that mod.
the energy does infact not have to be EU it can be MJ aswell not sure about whatever it is that Universal Electricity uses works though just connect buildcraft pipe to the MFFS extractor and your good to goThe thread on the IC2 Addon thread is found here. It has a link to the Direwolf20 Mod Spotlight, which goes into some detail.
Basically, Forcium around a diamond makes a forcium crystal which is a component in making MFFS machines. You can NEI that. Forcium is also fuel in MFFS machines to power the force fields themselves (requires a LOT of Eu to generate it as well).
Ahh, I was not aware the MFFS Extractor could hook up to MJ as well, that's pretty nifty. I figured since it was an IC2 addon that it would just run on Eu.the energy does infact not have to be EU it can be MJ aswell not sure about whatever it is that Universal Electricity uses works though just connect buildcraft pipe to the MFFS extractor and your good to go