Effect of chemical impurities on scheelite fluorescence

Recent widespread use of the ultraviolet lamp for scheelite prospecting has aroused interest in the variations in fluorescent colors displayed by this mineral. On the basis of 54 spectrographic analyses of scheelite samples whose fluorescence ranged from pale blue through white to yellow, it appears that the color variation may be related to quantitative variations in certain impurities. The molybdenum content of the scheelite increased from a trace in those specimens fluorescing blue to a maximum in material with yellow fluorescence. Manganese acted in a somewhat similar manner; the other elements showed no systematic variation.