Two-Color Longwave UV Fluorescent Specimen from Grenville-Sur-La-Rouge, Québec, Canada

Contributed by: FMS Admin
Date: May 14th, 2026
Locality: Grenville-sur-la-Rouge, Argenteuil RCM, Laurentides, Québec, Canada (See on Mindat)
Size: 5.9 x 4.3 x 8.9 cm

Description:
This specimen consists of a combination of scapolite, with an unidentified mineral that glows very bright light blue under longwave UV. This mineral glows almost as bright as English fluorite, but a very different color, which makes me doubt it is fluorite.

The scapolite fluoresces a nice bright yellow under longwave, but is quite weak under midwave, and barely reacts to shortwave.

Under midwave, a weak red fluorescing mineral (calcite?) shows up; and under shortwave, small spots of a very bright blueish-white fluorescing unidentified mineral show up.

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

Fluorescence under longwave UV light.

Fluorescence under midwave UV light.

Fluorescence under shortwave UV light.

Normal light.

Summary of luminescence responses:

Scapolite (Mindat) (RRUFF)

• Fluorescence under Longwave (365nm LED) UV light: Yellow