From left to right: Fluorite, Scheelite, Scapolite, Scapolite

Equipment: 

• Fluorescent mineral collection
• Collection of fluorescent liquids
• UV light (box light, use short wave)

Demo:

1. Turn off the lights in the room to make sure you  have a dark area.
2. Shine the UV light on the rocks to see their fluorescent properties.

Explanation: 

All materials reflect light and that is what makes them visible. These minerals also have the ability to absorb a small amount of light and release light at a different wavelength. This causes a change in color to the human eye. This effect is best seen when the minerals are illuminated by ultraviolet light, because it has a shorter wavelength than visible light. Ultraviolet light is not visible to the human eye. Its wavelength ranges from 100-400nm. The shorter the wavelength, the better the light is for observing most fluorescence. It is better, because it has a shorter wavelength than visible light, thus oscillating more and carrying more energy per photon.

Fluorite, Scheelite, Scapolite, Scapolite

How Fluorescence works:

1.  Photons from the UV light hit electrons within the atom.
2. The energy given to the electron excites it and jumps up to a higher orbital.
3. It then drops down to the ground level in steps, emitting two or more photons with lower energy and a longer wavelength. This light is in the visible portion of the spectrum.

Written by Nick McCabe