A 15 – 20 minute charge under sun, day or artificial light produces an afterglow of more than 12 hours. The brightness and type of light source that charges the GlowStone have an influence on its light duration and intensity.
Direct and indirect sunlight are the best light sources to achieve a good and sustainable light intensity with the GlowStone.
Black light is the second most efficient light source to charge the GlowStone. A few seconds under black light makes the GlowStone glow more intensely than a 10-hour charge from a light bulb. Experience shows that the GlowStone reaches 80% of its capacity in a few seconds under black light, but takes approx. 15 – 20 minutes to fully charge.
Fluorescent bulbs emit more ultraviolet light, which makes them more efficient than conventional light bulbs. Incandescent – Regular Light Bulbs: A 100 watt incandescent light bulb as a charging source, has only about 10 – 25 watts that are working to actually charge the pigment. Therefore, a 60 watt black light bulb will far outperform the higher powered white light.
Luminosity & duration
The grain size of the GlowStone has an influence on the light duration and charging time. Larger grains glow brighter and longer, but take more time to charge. In principle, it is possible to speak of complete charging after a charging time of 20 minutes, irrespective of the grain size, provided that this was carried out by suitable light sources. The luminous intensity of GlowStone depends on its colour. Emerald green has a higher luminance than turquoise or sky blue.
The GlowStone fulfils its purpose for more than 20 years in a cement or resin-epoxy matrix.
Stability of physical and chemical properties
GlowStone works ideally at temperatures between -30ºC and +500ºC. It is resistant to high and/or prolonged exposure to ultraviolet radiation and does not even discolour under a 300-watt mercury lamp for 1000 hours at 35ºC – 40ºC, 80% humidity. GlowStone remains unaffected by most commercial chemicals. In addition, it is not affected by extreme climatic conditions, such as high heat and sub-zero temperatures, nor by moisture. It neither expands nor shrinks in concrete or other materials.