Same view as in photo GYP2a, here shown under SW ultraviolet light. Note how the fluorescence of the primary willemite in the ore clasts has been destroyed in the areas of visible alteration. In contrast, secondary willemite is present within the gypsum as irregularly dispersed, microscopic grains that collectively are responsible for the ghostly appearance of its fluorescence. No visible hint of this willemite is apparent under normal light conditions.
Identifier: GYP2b Locality: Sterling mine, Ogdensburg, NJ Specimen size: 16 x 10 x 7.5 cm (face shown measures 14.5 x 7 cm) Photo credit: Earl R. Verbeek
