Longwave vs Shortwave UV: A Beginner’s Guide to Fluorescent Minerals

Fluorescent minerals do not all react the same way to ultraviolet light. A specimen may glow strongly under one wavelength and weakly or not at all under another.

Longwave UV

Longwave UV is common in consumer black lights and many handheld flashlights. It is useful for screening specimens and viewing materials that respond strongly at longer wavelengths.

Shortwave UV

Shortwave UV uses higher-energy ultraviolet radiation and is important for many classic fluorescent minerals. Dedicated shortwave equipment requires appropriate safety precautions and eye protection.

Why listings should name the light source

A statement such as “fluorescent” is more useful when the wavelength or light type is known. That helps collectors understand what they are likely to see at home.

Browse our fluorescent mineral specimens.