How to use "unnatural" in a sentence

The air of the tube platform is hot and dry, and the lights weak and unnatural.

It wasn't the gauzy, insubstantial stirring of windblown flakes, but an unnatural and purposeful rising of an entire mound of white

After half a minute, all of the unnatural movement stopped, and the room rapidly grew warm again.

I was not very near, but there was something unnatural and inhuman about the face