Sunlight is enormously important for growth. In fact, there is no life possible without light. This same light that initially made growth possible also accelerates the process of molecular decay. As soon as plants, for example, are ready for harvesting, they must be used immediately or preserved efficiently. If they are exposed to sunlight after being gathered then decomposition may take place and this drastically reduces the level of bio-energy in the plant.
The “Fraunhofer” institute in Munich (Germany) believes this process of decomposition to be due to the radiation from the visible light.
In order to test this observation, chemical analysis by gaschromatography of rosewater, stored for two months in violet as well as in amber glass, was performed at this institute. It was clearly shown that within two months the amount of several important aromatic compounds decreased significantly following storage in amber glass. No change was observed in the sample stored in the violet-glass pointing, to quality protection against decomposition by visible light.
Since ancient times, mankind has tried to protect its most valuable products against the damaging effects of light. The early Egyptians, for instance, preserved their precious substances in gold or violet jars. Glass, which has been known for ages, is still one of the most widely used materials. However, most of the traditional colors used in glass packaging (clear, amber, blue and green) allow visible light to pass trough and therefore don’t offer enough protection against decomposition processes induced by visible light. Violet-glass does not allow light from the visible spectrum to penetrate (with the exception of violet radiation), but is transparent in the infrared spectrum. Black glass doesn’t allow any visible light to go trough and is also transparent in the IR spectrum. The most important difference between these two glass types is that black glass fully absorbs UVA and violet frequencies without allowing any transmission to occur, whilst the violet-glass is permeable for these frequencies. These wavelengths partially enter the violet-glass, giving it a unique quality: impermeable in the visible light spectrum from bleu to red but open to penetration of UVA, violet and IR frequencies. Due this special combination, sensitive materials stored in violet-glass are highly protected against the processes of decomposition caused by light influences from the visible spectrum and gives it the added benefit of the positive effects that result from UVA, violet and IR frequencies