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.
Blue Light Fluorescence – Who needs UV anyway?
Originally posted on Nature's Rainbows by Graham Fraser. We all are familiar with fluorescence caused by UV. But an ordinary blue...