Fluorescent Minerals


JavaApplet to Display Mineral Images 

Fluorescent minerals respond to ultraviolet light by producing a wide variety of colors in visible light. Ultraviolet light is invisible to the human eye. Special ultraviolet light sources with filters were used to produce the photos above. A normal light photo is shown followed by an ultraviolet light photo. Only a small fraction of minerals are fluorescent. Small amounts of impurities called activators are required for many minerals to fluoresce. Different activators can produce different colors in the same mineral.

To see a colorful slide show with a variety of fluorescent minerals, click on one of the following links:

Manual slide show with mineral names (use for slow or dial-up internet connections)
Automatic Internet Explorer Slide Show
Automatic Java Slide Show (for other browsers)
Browse images with frames and mineral names
Three wavelengths of ultraviolet lights are commonly used. Long-wave (LW) is the range found in low-cost "black" lights. Mid-wave (MW) and short-wave (SW) ultraviolet require special lights and filters. Around 80% of all fluorescent minerals respond to short-wave ultraviolet. A few specimens contain a variety of minerals that will respond to several UV wavelengths . Some minerals respond in a different color to a different UV wavelength. Fluorescent minerals can also exhibit phosphorescence, tenebrescence, and thermoluminescence.

For more information about fluorescent minerals, click here

The coating inside the common fluorescent light is based on a fluorescent mineral. Fluorescent lights contain excited mercury vapor that generates ultraviolet light inside the glass tube. This ultraviolet light  makes the coating on the inside of the glass tube fluoresce white. The fluorescent light was invented by French physicist Alexandre-Edmond Becquerel (1820-1891). Nikola Tesla (1856-1943) first used higher frequencies for more efficient fluorescent lighting. Fluorescence is seen in "neon" and "day glow" colors and the red color of rubies. New white LEDS actually emit ultaviolet and a flourescent material in the plastic converts UV to white light. Many laundry products contain a white fluorescing material that makes fabrics whiter. Synthetic fluorescent minerals are used to produce the phosphor color dots found in TVs and computer CRT displays. Cathodoluminescence is the light response produced by a mineral specimen or phosphor exposed to an electron beam in a vacuum. In some cases, mines have used ultraviolet light to locate the desired minerals. Short wave ultraviolet is also used in germicidal lights. Ultraviolet dyes and ink are also used in currency and biological research.

Fluorescent Mineral Screensaver and Wallpaper












Photographic Images (C) 2003 James O. Hamblen