Calcite, with Strong "Brief Intense Phosphorescence" - Estrie, Quebec, Canada

Contributed by: FMS Admin
Date: May 16th, 2026
Locality: Estrie, Québec, Canada (See on Mindat)
Size: 6.7 x 2.7 x 7.7 cm

Description:
This calcite specimen, with the typical red fluorescence (best MW, then SW, then LW, as it's often the case with red fluorescing calcites), is not quite exceptional. But I still thought it was worth showing, first because fluorescent calcites from the Estrie region (formerly "Eastern Townships") are not often shown online, but also because it has a stronger than usual "brief intense phosphorescence (BIP)" upon exposure to longwave.

I remain vague about the locale because the occurrence where this specimen was discovered by a friend of mine, who asked me not to disclose it.

Originally posted by Frédéric Messier Leroux on Nature's Rainbows in 2021.

Fluorescence under shortwave UV light.

Fluorescence under midwave UV light.

Fluorescence under longwave UV light.

Afterglow after exposure to longwave UV light (BIP).

Normal light.

Summary of luminescence responses:

Calcite (Mindat) (RRUFF)

• Fluorescence under Longwave (365nm LED) UV light: Orange
• Fluorescence under Midwave (305nm LED) UV light: Red
• Fluorescence under Shortwave (255nm LED) UV light: Red
• Afterglow after exposure to Longwave (365nm LED) UV light: Red