Fluorescence is a phenomenon in which certain materials are able to give off visible light after absorbing nearly invisible light of a certain wavelength, such as ultraviolet light. Fluorescent glass is unique in that it can appear ordinary under visible light and then can emit vivid colors when excited by certain wavelengths.

The fluorescence in glass occurs with the presence of rare earth elements (lanthanides), which absorb invisible UV photons and then emit visible photons in the range of 400-700nm so that we see color.

This experiment demonstrates how fluorescence occurs in glass!

Fluorescence mini lesson

The Experiment

After looking at the glass in normal light, darken the room and examine each piece of glass under the black light. What do you see now? You will notice a visible show of various colors from the “clear” glass due to the rare earth elements contained in the glass!

Fluorescence in glass has many applications including medical imaging and biomedical research, such as the use of fluorescence spectroscopy as a diagnostic and research tool in many fields of medical sciences.

Fluorescence is found in many materials that you may have at home, such as laundry detergents, petroleum jelly, turmeric, olive oil, tonic water, and ketchup. Teeth have natural fluorescence, but human-made dental crowns usually don’t.

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