Lamps for Viewing Fluorescent Minerals


The lamps used to locate and study fluorescent minerals are very different from the ultraviolet lamps (called “black lights”) sold in novelty stores. The novelty store lamps are not suitable for mineral studies for two reasons: 1) they emit longwave ultraviolet light (most fluorescent minerals respond to shortwave ultraviolet); and, 2) they emit a significant amount of visible light which interferes with accurate observation, but is not a problem for novelty use.

Scientific-grade lamps are produced in a variety of different wavelengths. The table above lists the wavelength ranges that are most often used for fluorescent mineral studies and their common abbreviations.

The scientific-grade lamps used for mineral studies have a filter that allows UV wavelengths to pass but blocks most visible light that will interfere with observation. These filters are expensive and are partly responsible for the high cost of scientific lamps.

fluorescent mineral lamps
UV lamps: Three hobbyist-grade ultraviolet lamps used for fluorescent mineral viewing. At top left is a small “flashlight” style lamp that produces longwave UV light and is small enough to easily fit in a pocket. At top right is a small portable shortwave lamp. The lamp at bottom produces both longwave and shortwave light. The two windows are thick glass filters that eliminate visible light. The larger lamp is strong enough to use in taking photographs. UV-blocking glasses or goggles should always be worn when working with a UV lamp.

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