Tugtupite , Quartz Locality: Kuannersuit (Kvanefjeld) plateau, Ilimaussaq complex , Narsaq , Kitaa (West Greenland) Province, Greenland ( Locality at mindat.org ) A very rich and aesthetically shaped specimen of the SUPER-FLUORESCENT and rare, cherry-red, beryllium silicate, tugtupite, in quartz matrix from the Ilimaussaq Complex in Greenland. The base has been sawed to enhance display. Ex University of Copenhagen and Richard Hauck Collection. 7.4 x 6.0 x 2.7 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Tugtupite
A pink-to-red Greenland beryllium feldspathoid — a tenebrescent stone that deepens in sunlight.
Intro adapted from Wikipedia (CC BY-SA).
Tugtupite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₄BeAlSi₄O₁₂Cl.
It crystallizes in the tetragonal crystal system (space group I-4). It is a member of the Cancrinite-sodalite, Sodalite structural group.
Key properties: Mohs hardness 4; specific gravity 2.33; Vitreous luster; optically uniaxial.
IMA symbol Ttp, IMA status: approved, named in 1963.
Replaces chkalovite in hydrothermal veins cutting sodalite syenite and syenite (Il¶³maussaq intrusion, Greenland); an alteration product in pegmatites in a differentiated alkalic massif (Lovozero massif, Russia).
It is found associated with Albite, analcime, aegirine, natrolite, tetranatrolite, chkalovite, lithian mica, epistolite, niobophyllite, monazite, rhabdophane, gerasimovskite.
The name refers to the occurrence at Tugtup agtak^o rfia, Greenland.