Quartz, Cave-In-Rock, Illinois

The Cave-In-Rock area of Hardin County, Illinois, is best known to collectors for its historical production of world-class specimens of fluorite. However, the mines of that area produced many other minerals as well, some of which are fluorescent. This is a specimen of quartz crystals from Cave-In-Rock that shows an interesting fluorescent response under both short and long wave UV due to the presence of hydrocarbon, and other organic, activators. The size of this specimen is 76 x 64 x 37 mm, and it weighs 184 grams.

Mouse over the scrolling images for wavelength information.

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