Fluorescent Halite, Detroit Salt Company Mine, Detroit, Michigan
Contributed by: Chris Clemens
minID: 4R9-CFY
Date: May 19th, 2026
Locality: Detroit Salt Company Mine (International Salt Company Mine), Detroit, Wayne County, Michigan, USA (See on Mindat)
Size: 42 x 21 x 67 mm
Weight: 38 g
Description:
Many people do not realize that located 1200 feet below the city of Detroit, Michigan, lies a massive, active, underground salt mine. The Detroit Salt Mine covers an area of more than 1500 acres and has over 100 miles of underground roads. The salt deposit dates back approximately 400 million years and resulted from the evaporation of sea water in the Michigan Basin. These photographs show a beautiful specimen of halite (rock salt) collected from the Detroit Salt Mine. Interestingly, halite from this location often shows an orange, fluorescent response under UV light, as can be seen in the photographs taken under shortwave and midwave UV light. Note the fluorescent zoning in the cubic crystals.
Originally posted by Chris Clemens on Nature's Rainbows in 2016.
Summary of luminescence responses:
Halite (Mindat) (RRUFF)
- Fluorescence under Shortwave (254nm Lamp/Mercury) UV light: Orange
- Fluorescence under Midwave (305nm Lamp/Mercury) UV light: Orange