Fluorescent Calcite and Scheelite from the Ophir Hill Mine, Tooele County, Utah

Tabular calcite crystals and small scheelite octahedrons on limestone matrix, from the Ophir Hill Mine, Ophir, Tooele County, Utah. At its best under short wave UV, the calcite shows a beautiful, intense, red response, and the scheelite fluoresces bright blue/white. The calcite shows a similar, but brighter red/orange response under mid wave UV, but the scheelite is not fluorescent under this wavelength. The long wave UV response is similar to mid wave, but dimmer. This specimen measures 9.5 x 9.0 x 6.2 cm, and weighs 498 grams.

Located in the Oquirrh (pronounced like “ochre”) Mountains, southwest of Salt Lake City, Utah, the Ophir Hill Mine operated between 1870 and 1972, and produced lead, zinc, silver, copper, manganese, and tungsten.

Under short wave UV (254 nm), the calcite fluoresces a saturated red/orange and numerous dipyramidal scheelite crystals shine like bright blue/white stars.

The calcite fluoresces brightest under mid wave UV (302 nm), but under this wavelength the scheelite is not fluorescent.

As shown above, the fluorescent response of the calcite is weakest under long wave UV (365 nm).

Same specimen shown under visible light.

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