Rocks That Glow Red Under UV Light

Calcite Glows Red

• Calcite will glow red under a ultraviolet light. Most rocks that are fluorescent are actually filled with impurities and the impurities are the components of the rock that glow, rather than the rock composite itself. The trace amounts of manganese in calcite is the part of the rock that glows red after UV exposure.

The Science Behind the Red Glow

• A rock reflects part of the wavelengths of standard light, thus producing its color. When exposed to ultraviolet light, the rock will actually become a light source and generate a different light color, depending upon its composition. Furthermore, when the UV light is removed, the rock will glow red because the energy from the UV light has been absorbed by the impurities in the rock and now is released as red light.

Exploring for Rocks

• Certain caves are well known for having certain impurities, or ores. When searching for your red glowing rock, you must take a UV light and explore at night as the red wavelengths are almost imperceptible in the daylight. Exploring deep into the mines provides you with the best opportunity to find red glowing rocks. However, there are several risks including difficult terrain, unsafe areas and scorpions or bats. The Anza-Borego Desert near San Diego, California contains a mine that is well-known to contain massive amounts of calcite.

Phosphorescence in Everyday Life

• Phosphorescent particles in your laundry detergent activate the fibers in your white clothing to shine brightly in normal daylight. Fluorescent lights, including compact fluorescent light bulbs, emit a particular white wavelength of light from fluorescent reactions. Day-glo orange clothing commonly used by hunters or roadside construction workers shine brightly from fluorescent pigments in the fabrics used. Calcite used as a pigment base in specialized paints allows you to paint with red glowing paint.