Fluorescent Minerals - Physics Demonstrations - Fluorescent Minerals | Physics Undergraduate Labs

Both short-wave and long-wave UV sources emit radiation harmful to eyes and skin. Never look directly at UV lamps. Short-wave UV (254 nm) is particularly dangerous and can cause corneal burns with brief exposure. Limit direct skin exposure. Consider using UV-blocking safety glasses when handling UV sources at close range for extended periods.

Purpose

Demonstrates fluorescence and atomic energy level transitions using mineral collections under short-wave and long-wave UV light. Students observe wavelength-dependent excitation and Stokes-shifted emission, and several samples also show phosphorescence from metastable states.

Collection of about 30 mineral samples under long-wave UV light, fluorescing in blue, green, orange, purple, pink, and yellow against a black background

Same mineral collection under short-wave UV light showing different fluorescence pattern with brighter red, green, and orange emissions from different samples

Same mineral collection under white light, appearing as ordinary gray, white, tan, and brown rocks

Figure 1: Mineral collection under long-wave UV (365 nm). Different minerals emit characteristic visible colors depending on their activator ions and energy level structure.

Figure 2: Same collection under short-wave UV (254 nm). Note the dramatically different response — some minerals that were dark under long-wave UV now fluoresce brightly, and vice versa.

Figure 3: Under white light, the same minerals appear as ordinary rocks. Show this first for dramatic contrast when switching to UV.

Safety Warnings

Warning: UV Radiation Hazard

Purpose