Calcite on Limonitic Gossan - Montreal Mine, Wisconsin
Contributed by: Chris Clemens
minID: DN6-7HJ
Date: May 3rd, 2026
Locality: Montreal Mine, Montreal, Gogebic Range, Iron County, Wisconsin, USA (See on Mindat)
Size: 68 x 38 x 98 mm
Weight: 181 g
Description:
This is an interesting fluorescent calcite specimen from a location not generally known for producing fluorescent minerals. From the Montreal Mine in Iron County Wisconsin, it consists of small, grey-colored, platy crystals of calcite on a contrasting red/brown matrix of limonitic gossan. The calcite shows a pink, fluorescent response under all UV wavelengths, but is brightest under midwave UV. The response under shortwave and longwave is only dim to moderately bright.
The Montreal Mine was an iron mine located near the town of Montreal, in northern Wisconsin. Production at the mine ceased in 1963. This location is known to produce calcite specimens that show hot pink fluorescence, such as this one.
Originally posted by Chris Clemens on Nature's Rainbows in 2018.
Summary of luminescence responses:
Calcite (Mindat) (RRUFF)
- Fluorescence under Midwave (305nm Lamp/Mercury) UV light: Pink