Green Fluorescent Sodalite from China

Contributed by: Michael Crawford
Date: Jun 8th, 2025
Locality: Akesu Prefecture, Xinjiang, China (See on Mindat)
Size: 5 x 4 x 7.5 cm

Description:
Green fluorescence is uncommon for sodalite. These two sodalite specimens from Akesu, Xianjiang Province, China fluoresce a greenish hue in SW illumination. XRD analysis confirmed the identification of sodalite. The SW emission spectra have a peak at 494 nm which is at a shorter wavelength compared to the peak of green, fluorescent willemite at 524 nm. The SW emission spectra have a single peak rather than multiple peaks characteristic of uranyl activation. The single peak suggests that manganese is a possible activator like willemite.

The specimens have slightly different fluorescence in LW illumination. Sodalite-1 specimen fluoresces orange and Sodalite-2 fluoresces yellow orange. The spectra of both specimens have low amplitude vibronic peaks superimposed on the broad peak. These vibronic peaks are caused by a disulfide activator and are characteristic of LW sodalite fluorescence. Sodalite-1 has a second broad peak with a maximum around 430 nm. This fluorescence may be activated by dioxide (Emmermann, 2010). Titanium or missing oxygen atoms in the sodalite cage could also be responsible for this blue fluorescence. A vein of blue, fluorescent fluorite crosses Sodalite-1.

Sodalite-1 is 7.5 cm by 5 cm.
Sodalite-2 is 8 cm by 6 cm

Emmermann, A. (2010) Fotochromisme en fluorescentie in sodaliet, variëteit hackmaniet [Photochroïsm and fluorescence in sodalite, variety hackmanite]. Geonieuws, 35 (06) 128-132