Red Fluorescent Barite, Custer County, Colorado

Contributed by: Chris Clemens
minID: 123-6EC
Date: Apr 19th, 2026
Locality: Silver Cliff Mining District, Custer County, Colorado, USA (See on Mindat)
Size: 46 x 28 x 65 mm
Weight: 115 g

Description:
This specimen was collected from an old barite mine (unidentified) in the general location of Silver Cliff, Custer County, Colorado. It shows an interesting specimen consisting of brecciated clasts of light tan baryte in a dark brown matrix of unknown composition. The baryte clasts show a beautiful orange to red fluorescent response under all UV wavelengths, brightest under shortwave. This is an unusual fluorescent response for barite. Most fluorescent barite responds to UV with pale white, blue/white, or cream/white fluorescence, so these show atypical fluorescence.

Originally posted by Chris Clemens on Nature's Rainbows in 2020.

Fluorescence under shortwave UV light.

Fluorescence under midwave UV light.

Fluorescence under longwave UV light.

Normal light.

Summary of luminescence responses:

Baryte (Mindat) (RRUFF)

• Fluorescence under Longwave (365nm LED) UV light: Red
• Fluorescence under Midwave (305nm Lamp/Mercury) UV light: Red
• Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Red