Natrozippeite - Little Eva Mine, Grand County, Utah
Contributed by: Chris Clemens
minID: 0V1-HL9
Date: Apr 27th, 2026
Locality: Little Eva Mine, Yellow Cat Mesa, Thompsons Mining District, Grand County, Utah, USA (See on Mindat)
Size: 15 x 11 x 22 mm
Weight: 4 g
Description:
Natrozippeite, also known as sodium zippeite, is a secondary hydrous sodium uranium sulfate that commonly forms as efflorescent encrustations on sandstone in underground uranium mines in the western US. As is the case with many secondary uranium minerals, natrozippeite is brightly fluorescent under UV. This specimen features small yellow crystals of natrozippeite on a sandstone matrix, collected from the Little Eva mine, located north of Arches National Park, in Grand County, Utah. The natrozippeite shows a bright yellow/green fluorescent response under all UV wavelengths. Because this mineral contains uranium, it is radioactive, and emits approximately 2000 cpm.
Originally posted by Chris Clemens on Nature's Rainbows in 2017.
Summary of luminescence responses:
Natrozippeite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: Green
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Green