Multicolor Fluorescent Calcite from the Area of Gatineau, Quebec, Canada
Contributed by: FMS Admin
Date: May 15th, 2026
Locality: Gatineau TE, Outaouais, Québec, Canada (See on Mindat)
Size: 6 x 1.2 x 6.7 cm
Description:
In daylight, this specimen is something most collectors would not even bother looking at; but since I knew calcite from this locale, especially "optical calcite", can be pretty gorgeous in midwave UV. I decided to look at this non-gemmy, white calcite cleavage under midwave, and I did not regret taking time to do so.
This specimen is at its best under MW and LW combined; most colors are the reaction of this specimen to MW; however, small zones of yellow fluorescence are brighter under LW. The areas that fluoresce bright red under midwave shift to a yellow-orange color under shortwave. The SW response is weaker than MW. Nice specimen for a midwave UV display.
Originally posted by Frédéric Messier Leroux on Nature's Rainbows in 2021.
Summary of luminescence responses:
Calcite (Mindat) (RRUFF)
- Fluorescence under Longwave (365nm LED) UV light: White
- Fluorescence under Midwave (305nm LED) UV light: Red
- Fluorescence under Shortwave (255nm LED) UV light: Orange