I posted this on WotC's D&D forum but I thought I'd get the opinions of the planewalkers on this one:
Does this mean genies and mephits aren't composed of the "material" of the elemental planes they are native to? Were they some other type of creature before coming to the elemental planes and becoming Outsiders?
I don't quite understand the distiction between Outsiders and Elementals when it comes to genies and mephits. Their nature makes them seem closer to Elementals than to Outsiders.
Also, while I'm on the subject, since the "Planar Golems" in Monster Manual III are "made from the matter of an Outer Plane" wouldn't that make them more like "Outer Plane Elementals" than constructs?
-420
Mephits, IIRC, aren't wholly made of pure elemental matter. There's a bit of something else inside them. Also noteworthy are the many types of mephits that aren't The Big Four of 3rd ed cosmology - Dust and Ooze aren't 'pure' elemental material in 3E and onwards.
Genies are even more clearly outsiders - they draw strongly on elemental essence for vitality and power, but are made up of muscle, skin and bone. They're outsiders, not elementals.
As for the outer planar golems, there's no way they're elementals. They're formed of the matter and power of an outer plane, which is rarefied belief and ideal given form, not elemental matter. There's no such thing as "Arcadian" or "Ysgardian" elemental matter, and so beings formed from the appropriate planar stuff aren't elementals.