This item is not glow in the dark, they contain uranium which reacts to UV light (shown here under 395nm). Background radiation is around 20-50cpm to give you an idea of how weak it is, they are perfectly safe.
Hazel Atlas Eyeball Personal Ashtray 3.75" Depression Uranium Vaseline UV Glow
Uranium Vaseline UV Reactive Glass Filled Potion Bottle Vial
VINTAGE Art Deco Uranium Vaseline Glass Perfume Bottle w/ Stopper | Glows UV
20 x URANIUM / VASELINE GLASS SMALL MARBLES (10 mm) SHOWING UV FLUORESCENCE
5 x URANIUM / VASELINE GLASS SMALL MARBLES (10 mm) SHOWING UV FLUORESCENCE
Fenton Custard Glass Bell Hand Painted Floral Uranium Vaseline Glows UV Vintage
