These fluorite slices originated in the Inner Mongolia region of China. The fluorite nodule formed around a mineral inclusion[s] and, over time, additional layers of fluorite formed. The further from the inclusion [brown color], the lighter the green shade of the fluorite. The nodule was then cut and polished to create this end slice. The fluorite is somewhat transparent and lower layers can be seen from the cut and polished surface. While shortwave ultraviolet light exposure doesn't create the brightest fluorite fluorescence, it does permit the inclusion to fluoresce better than the other wavelengths. Weight is 4 pounds 4 ounces and measurements are 4 1/2 x 3 1/2 x 1 1/2 inches. ISO-100 f/11 2.5 seconds exposure for the fluorescent pictures. Order of presentation: SW, SW exterior, LW, MW, natural, natural exterior.