Mineral Specimen #6678 Calcite on Quartz with Micro Pyrite Crystals
Guanajuato, Guanajuato, Mexico
21.6 x 6.8 x 5 cm
8.5 x 2.7 x 2 in
Ex. A. E. Seaman Mineral Museum, Dean Collection, 197'
Although the label only says 'Mexico' for the location the specimen is from one of the Silver mines in or around the city of Guanajuato. This assumption is based on the habit of both the Calcite and Quartz and the fact that the Quartz does show a little Amethyst color on the bottom of the specimen (and the fact that I have had many specimens from Guanajuato over the years). The label reads 'splendid fluoresces' which is true to a degree. Under LW, the Calcite fluoresces a yellow color and seems to glow from within. It appears there is a thin, nonfluorescing, clear layer of Calcite over Calcite that does fluoresce. This is highlighted by the fact that there are several places where the Calcite is damaged/bruised, which although not noticeable under visible light, fluoresce a bright white/blue under LW. Under SW, the Calcite fluoresces orange, but the same effect of seeming to fluoresce from within is absent but the damaged areas are still a bright white/blue. However, under neither SW nor LW, the fluorescence is not very bright which is why there are no fluorescent photos (under LW, the fluoresces is stronger). That being said, the larger Calcite is quite nice.
Flaws: A few of the smaller Calcite crystals are incomplete which is not noticeable except under UV.
This mineral is also found in the following galleries: Minerals From Mexico | Calcite | Quartz | Sulfides and Sulfosalts | Minerals Priced Between 25 and 49 Dollars