An old video with a quick explanation of the light spectrum and why 365nm is important to us as fluorescent mineral collectors (as well as filters) compared to 385nm LED lights (without filters). Of course this video is trying to sell something: a 365nm LED light for >$1,000. Obviously there are better alternatives now, but it is a good explanation of UVA (longwave) and visible light.
What is Tenebrescence?
In the early 1800's geologists noted that some specimens of sodalite from Greenland exhibited a bright pink color on freshly broken...