Sodalite, a rich royal blue mineral, is what fluoresces underneath the ultraviolet light. (This means the sodalite absorbs the UV light and then emits it at a different wavelength, which is why it appears fiery orange.)

Does sodalite glow?

Specifically – the rock in question is partially composed of a mineral called “Sodalite”, which is a fluorescent mineral. Electromagnetic radiation (here light from the UV flashlight) at one wavelength is absorbed by the mineral, which then re-emits radiation at a longer wavelength – in this case, the yellow glow.

Does sodalite react to UV?

Sodalite rocks can even be boulders several metres in diameter. Some not only change colour but also fluoresce when charged with UV light. But the process is reversible and they switch back to their original colour when placed in regular sunlight.