AD&D 2nd Edition Planescape Monstrous Compendium Appendix III (1998)
Steve: Paraelementals are way cooler than regular elementals. It's like, about boundaries and between states.
Zack: I think it's about their need to come up with more versions of the same monsters, but they couldn't do a Diablo palette-shift.
Steve: What? Paraelementals are classic. Gygax dreamed them up. They come from the paraelemental planes. Where the elements mingle.
Zack: Where does the ice come from?
Steve: Where air meets water.
Zack: That would be soda or something. Ice would be where cold meets water.Steve: A-ha, but cold isn't an element, it's negative energy. From the negative energy plane.
Zack: So what happens when water and negative energy plane combine?
Steve: They don't touch, water touches the negative material plane and makes salt.
Zack: They form the paraelemental plane of salt?
Steve: No, salt is quasielemental not paraelemental.
Zack: Burn forever.
Steve: That would be on the elemental plane of fire.