[Inquisitive1]

I've learned that luminescence is quenched by heavy atoms, such as the halogens and amines.

But do other heavy atoms also quench fluorescence/phosphorescence?

For example, the alkali / alkali earth metals. They are obviously quite heavy as well.

Yet elements like radium are naturally phosophorescent -- so I suppose radium is not a good quencher?

[Arkcon]

Well, luminescence, fluorescence, and phosphorescence of large organic molecules generally arise from electron transitions across multiple conjugated double bonds.  Many things can "steal" the energy from those bonds before it can be released as light, and we give those the blanket term of "quencher."  I don't really know why radium has a native luminescence, or how such phenomena are associated with minerals, but these may be atomic transitions, that can't be quenched in the same way.

[Inquisitive1]

Actually, on further review, I'm not sure that radium qualifies as naturally phosphorescent.

I had originally presumed that because radium was historically used in phosphorescent glow-in-the-dark paints.

But as it turns out, it's not the radium itself that's phosphorescing. Rather, the radiation emitted by the radium in the form of alpha particles (and by subsequent decay products, in the form of beta particles and gamma rays) causes electronic transitions in neighboring phosphorescent compounds. Usually copper or magnesium doped zinc sulfude (ZnS).

Which brings me back to the original question -- are heavy elements like radium capable of quenching fluorescence and phosphorescence?

If you had a fluorophore in solution, and you brought it into close contact with radium, would its fluorescence be quenched?