Using a black light for generating glowing effects is easy when using ice cubes made of tonic water. Tonic water contains a crystalline alkaloid called quinine, which makes water glow an eerie blue when cast under a black light. Quinine is used effectively for treating and preventing malaria, easing leg cramps and reducing fevers. It was originally used in water as an additive to enhance the flavor when administered medicinally. This project would have to be encased in a dark box for the full glowing effects to be appreciated, and it could include sufficient information regarding the unusual properties of quinine, along with an explanation on how black lights function.
Glowing ice can be made by using a concentrated coloring agent. Atomic Glow is a liquid substance that will produce glowing ice when combined with water prior to freezing. It is essentially a luminous zinc sulfide. You can also create a large glowing sphere by freezing a balloon filled with water and atomic glow. A substance similar to Atomic Glow has been used for fighter pilots. When forced to jump out of a plane, the pilot's backpack, full of the atomic powder, would burst, making it easier for search and rescue teams to locate him. This is a fun and informative way to learn the difference between fluorescent and phosphorescent substances.
You can create a large, glowing sphere of ice by using a light-emitting-diode (LED). This project requires an LED, a balloon, charging wires, electrical tape, water and batteries. Connect the wires to the LED and cover, first individually and then together, with electrical wire. Place the LED into a balloon with the wires hanging out the end. Fill with water and freeze. Once adequately frozen, remove the rubber and attach the batteries to the wires. This is a great lesson in electrical conduction.
If you have concerns with ice melting, you can create faux ice by using clear casting epoxy. Mix an ample amount of solution to suit your needs by using equal parts resin and hardener. Before it hardens, place the LED into a cube tray, the sphere or whatever shape you desire. Make sure that the LED wires are free from the mold so as to easily assemble a connection once hardened. To further enhance the ice factor of this project, consider using dry ice around the display.