These marbles are all displayed in a black light cabinet that hangs on our wall. It's an antique cabinet than I rigged up with a black light in order to display these marbles nicely in. All of the marbles have one of three things in them - either vaseline (Ultraviolet/UV/Radioactive) glass or lunaris powder (glass that glows in the dark and keeps glowing after the light is turned off) or a soft yellow glass that likes to turn orange-ish with the black light.