Lava Element Questions

I have a question. A firebender and an earthbender are fighting, say, in a lava feild. And lava sprouts up and the firebender uses it, because he is that good. Can the earthbender bend lava to? After all it IS just liquid rock, therefore, it is earth, therefore, bendable by an earth bender. Nextly, when is a firebender ever seen bending lava? The only firebenders we see doing this are also avatars and therefore, we never know if they are using earthbender or firebending to bend it. And since it IS liquid rock, and firebending is shown to bend no objects with physical substance, only ethereal fire and lightning, isn't it most logical to assume lava is earthbending as far as advanced elements go?

Edit: (looking back I even think Roku was using earthbender-like motions to bend it, instead of firebender stances. But it was a long time ago)

Well to solve the issue of when did we see lava used, it dosnt matter, this is a non canon site and we have extended the limits of creative ideas from the show to our own.

also, we stated in the rules in order to bend lava, you must train with a earth bender to learn their motions, not earth bending. Yes there is a small aspect of earth bending when it comes to lava, but we have classified it as a heat element, Now if the lava were to suddenly be cooled to the point where it is soild rock now, a earth bender may use it and not a fire bender. There is a thin line between these, but they are set rules.

i hope any of that has helped.