| Hardystonite
{Ca2ZnSi2O7}: FL
Blue-Violet SW Calcite {CaCO3}: FL Red-Orange SW Willemite {Zn2SiO4}: FL Green SW This is another specimen I found on the Buckwheat night dig of November 5, 2005. Hardystonite, calcite, and willemite make a beautiful combination under the short-wave lamp, as you can see from the photograph. Like most other fluorescent minerals, hardystonite can have varying brightness. Some specimens are very bright, while others are quite dim. Some hardystonite responds weakly under long-wave (LW) as well as short.. This rock in daylight has a peculiar weathering on one part of the hardystonite. The franklinite grains have halos around them that resemble dendrites of some manganese mineral (pyrolusite?), in turn surrounded by a white coating that appears to be some kind of alteration of hardystonite. It may in fact be hardystonite that was simply redeposited as a secondary coating. The rocks that have this alteration generally have a certain look to them, right down to the consistency of the calcite and franklinite.  Note that this is the "back" of the specimen. Below is a photograph of the same area in short-wave UV:  |
