Greenland Fantasy Rock, a Spectacular, Multi-Colored Fluorescent Treat from the Taseq Slope

Contributed by: Chris Clemens
minID: 8AV-FC4
Date: Apr 20th, 2026
Locality: Taseq Slope, Ilímaussaq complex, Kujalleq, Greenland (See on Mindat)
Size: 8.6 x 7.4 x 14.3 cm
Weight: 1120 g

Description:
This is an excellent example of Greenland Fantasy Rock, showing a beautiful multi-colored, multi-wavelength fluorescent response under various UV wavelengths. The term "Fantasy Rock" was coined by Greenland Mineral collector Mark Cole (and creator of the Nature\'s Rainbows website), and refers to a group of rocks found on the Taseq Slope within the Ilimaussaq Complex in the Narsaq area of southern Greenland that typically contain an assemblage of brightly fluorescent tugtupite, sodalite, analcime, and chkalovite. Light colored analcime and green/grey sodalite provide a matrix for pink tugtupite and black needle-shaped crystals of arfvedsonite. This rock is mildly radioactive, and emits approximately 200-300 cpm. The following photographs illustrate the striking multi-colored, multi-wavelength nature of the fluorescent response of Greenland Fantasy Rock.

Cherry-red fluorescent tugtupite and pale blue analcime dominate the fluorescent response under shortwave UV, with patches of sodalite showing subdued orange fluorescence and chkalovite green. A similar response is seen under midwave UV, but the response of the tugtupite shifts to a more orange color and the sodalite is a bit brighter. Under longwave UV the tugtupite fluoresces a salmon-orange color; and the sodalite comes alive, showing a fiery bright orange response.

Originally posted by Chris Clemens on Nature's Rainbows in 2019.