Some require special lighting or viewing conditions to see this phenomenon.
Geology.com recently published a fabulous article about fluorescence that I hope you will enjoy.
What is a Fluorescent Mineral?
All minerals have the ability to reflect light. That is what makes them visible to the human eye. A few minerals have an interesting physical property known as “fluorescence”. These minerals have the ability to temporarily absorb a small amount of light and an instant later release a small amount of light of a different wavelength. This change in wavelength causes a temporary color change of the mineral in the eye of a human observer.
The color change of fluorescent minerals is most spectacular when they are illuminated in darkness by ultraviolet light (which is not visible to humans) and they release visible light. The photograph above is an example of this phenomenon.
Fluorite was the original fluorescent mineral. Fluorite is a beautiful gemstone that’s available in a lot of colors and makes lovely jewelry.
Fluorescence in More Detail
Fluorescence in minerals occurs when a specimen is illuminated with specific wavelengths of light. Ultraviolet light, x-rays and cathode rays are the typical types of light that trigger fluorescence. These types of light have the ability to excite susceptible electrons within the atomic structure of the mineral. These excited electrons temporarily jump up to a higher orbital within the mineral’s atomic structure. When those electrons fall back down to their original orbital a small amount of energy is released in the form of light. This release of light is known as fluorescence. .
To learn more about fluorescent minerals and gems, visit http://geology.com/articles/fluorescent-minerals/