Fluorescent Mineral Database

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Botryoidal Fluorite from Colorado

Contributed by: Michael Crawford
Date: Jul 3rd, 2025
Locality: Unnamed fluorite occurrence, Fourmile Creek Area, Fremont County, Colorado, USA (See on Mindat)
Size: 7 x 10 cm

Description:
Purplish-gray botryoidal fluorite from Fourmile Creek, Canon City, Colorado. Fluorite in botryoidal form is quite uncommon, and the fluorescence is also an unusual green color. It has no longwave fluorescence but fluoresces green in midwave and shortwave UV illumination. The emission spectrum for the fluorite exhibits vibronic peaks characteristic of uranyl activation. The radioactivity emitted by this specimen is around 130 CPM.

Fluorescence under shortwave UV light.
Fluorescence under shortwave UV light.
Normal light.
Normal light.
Shortwave Emission Spectrum of Fluorite
Shortwave Emission Spectrum of Fluorite

Summary of luminescence responses:

Fluorite (Mindat) (RRUFF)

  • Fluorescence under Midwave (305nm LED) UV light: Green
  • Fluorescence under Shortwave (255nm LED) UV light: Green

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