Why is it impossible to induce fluorescence in water? Is it because of missing electrons that can do the fluorescence process, or other reasons?
Do all materials with fluorescence always visible? If there is only a trace of it, then it's not visible to the eyes?Gaseous water is reported to have lased at 118.6um (https://link.springer.com/article/10.1007/BF00694636).
So you may be able to get it to fluoresce at that wavelength as well.
This is in the far infrared region - far from visible.
Being colorless and transparent, I would not have expected it to absorb or emit in the visible range.
The key to florescence is electron energy levels. You need to be able to bump one of its electrons to a higher shell and allow it to fall back. So the "color" will depend on the energy levels available in the molecule's electron shells.