"Fantasy Rock" from Taseq West, Ilímaussaq complex, Kujalleq, Greenland

Contributed by: FMS Admin
Date: May 14th, 2026
Locality: Taseq Slope, Ilímaussaq complex, Kujalleq, Greenland (See on Mindat)
Size: 5.5 x 4.7 x 9.2 cm

Description:
Here is a nice "Fantasy Rock" that I recently acquired. It contains only modest amounts of tugtupite, occurring as replacement rims around chkalovite; but it contains quite a lot of sodalite, chkalovite and analcime, which make it nicely reactive to all UV wavelengths (much less striking under longwave than under shortwave and midwave, as usual). What makes this specimen interesting to me is the fact that it contains chkalovite that fluoresces two different colors under shortwave (mostly bright pearl-white, but also a small amount on the right side of the specimen that fluoresces violet), and it contains a decent amount of tenebrescent sodalite.

Under shortwave, the specimen is definitely at its best; but the midwave response is also quite interesting. Under midwave, the pearl-white fluorescing chkalovite shifts to a yellowish color; as usual, the tugtupite shifts to a salmon-orange color like under longwave, and the analcime is bright blue, like under shortwave. The chkalovite, tugtupite and some of the sodalite are phosphorescent upon exposure to shortwave. Small amounts of yellow fluorescing polylithionite show up under SW. Uranyl salts fluoresce bright green under SW and MW.

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