Liebigite - Schwartzwalder Mine, Jefferson County, Colorado

Contributed by: Chris Clemens
Date: Apr 25th, 2026
Locality: Schwartzwalder Mine (Ralston Creek Mine), Ralston Buttes Mining District, Jefferson County, Colorado, USA (See on Mindat)
Size: 38 x 21 x 39 mm
Weight: 42 g

Description:
Yellowish green scales of liebigite on schist, from the Schwartzwalder Mine, Jefferson County, Colorado. Liebigite is a secondary uranyl carbonate mineral that shows a brilliant blue/green, fluorescent response under UV, most brightly under shortwave. Being a uranium-containing mineral, liebigite is moderately radioactive. This specimen emits approximately 1500 cpm at 1 cm.

Originally posted by Chris Clemens on Nature's Rainbows in 2016.

Fluorescence under shortwave UV light.

Fluorescence under longwave UV light.

Normal light.

Summary of luminescence responses:

Liebigite (Mindat) (RRUFF)

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