Calcite, Willemite and Fluorite - Hogan Claim, Wickenburg area, Arizona
Contributed by: Chris Clemens
Date: Apr 26th, 2026
Locality: Great Southern Mine, Monarch Wash area, Black Rock Mining District, Yavapai County, Arizona, USA (See on Mindat)
Size: 7.3 x 3.9 x 7.9 cm
Weight: 289 g
Description:
This spectacular rock contains an assemblage of fluorescent calcite, willemite and fluorite in a brown/red-colored groundmass and is from the Hogan Claim (Hogan Mine), Wickenburg area, Yavapai County, Arizona. Under shortwave UV the fluorite fluoresces deep blue, the calcite red, and the willemite light green (with lasting phosphorescence). Under longwave UV the fluorite shows a bright blue response and the calcite fluoresces a dim red.
The Hogan Claim is a former fluorspar, silver, gold, lead and molybdenum mine, and is located near Red Picacho Peak in the Wickenburg area. It is also located on the same mountain as the Purple Passion Mine, another prolific source of fluorescent mineral specimens.
Originally posted by Chris Clemens on Nature's Rainbows in 2017.
Summary of luminescence responses:
Calcite (Mindat) (RRUFF)
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Red
- Fluorescence under Longwave (365nm LED) UV light: Blue
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Green
- Afterglow after exposure to Shortwave (254nm Lamp/Mercury) UV light: Green