Same view as in photo GYP9a, here shown under SW ultraviolet light. The zincite in the specimen shown above fluoresces yellowish-green (muted here, but much brighter LW) while the associated gypsum fluoresces bright blue. The blue-fluorescent crusts in samples from the Palmerton smelter had long been assumed to be hydrozincite, a logical assumption given their association with zincite in a porous material exposed to the atmosphere and moisture from precipitation. However, Raman spectra of several samples (Verbeek and Penny, 2022) showed they are gypsum instead.
Identifier: GYP9b Locality: Sterling mine, Ogdensburg, NJ Specimen size: 6 x 4.5 x 3 cm Photo credit: Ryan N. Penny
