Fluorescent Calcite on Dolomite - Sainte-Clotilde-De-Châteauguay, Quebec, Canada
Contributed by: FMS Admin
minID: U5X-MM6
Date: May 17th, 2026
Locality: Sainte-Clotilde-de-Châteauguay quarry (Marcil quarry), Sainte-Clotilde-de-Châteauguay, Les Jardins-de-Napierville RCM, Montérégie, Québec, Canada (See on Mindat)
Size: 4 x 3.9 x 5.4 cm
Description:
The Sainte-Clotilde quarry (formerly Marcil quarry) near the village of Sainte-Clotilde-De-Châteauguay in Montérégie, Québec, now unfortunately closed to collectors (like so many other locales here in eastern Canada), was mostly known for "daylight minerals", and rarely referred to as a fluorescent mineral locality. But still, many specimens from there fluoresce nicely under UV; their LW response is usually bright enough for a LW display. Usually, calcite from this deposit is at its best under longwave, followed by midwave, and not very bright under shortwave.
Red and reddish pink LW fluorescence has been reported in some calcite specimens, but LW yellow and yellowish white seem to be the most common. Pink MW fluorescence is relatively common; and in some cases, crystals fluoresce both yellow and pink under MW. In most cases, SW is like LW but much weaker; this is the case with the specimen shown here. Therefore, I consider the SW response not worth being posted.
On some specimens, including this one, the dolomite shows a very weak pink response under longwave.
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: Pink