Some more camera work with the black light and rocks from the desert. Some specimens of Chalcedony fluoresce under long wave UV light appearing both green and less commonly yellow. While the majority of chalcedony specimens collected do not fluoresce those that do, stand out on the desert landscape at night under UV light and are easy to find. The short video below shows fluorescence from mineral and biological sources. The orange appears to be from some species of lichen which is brown under visible light but bright orange under UV while the remainder of the fluorescing specimens are chalcedony.