Tugtupite
Tugtupite is a rare beryllium aluminium tectosilicate. It also contains sodium and chlorine and has the formula Na4AlBeSi4O12Cl. Tugtupite is a member of the silica deficient feldspathoid mineral group. It occurs in high alkali intrusive igneous rocks.
Tugtupite is tenebrescent, sharing much of its crystal structure with sodalite, and the two minerals are occasionally found together in the same sample.
Tugtupite occurs as vitreous, transparent to translucent masses of tetragonal crystals and is commomly found in white, pink, to crimson, and even blue and green. It has a Mohs hardness of 4 and a specific gravity of 2.36. Tugtupite is also a non-radioactive substance. It fluoresces crimson under ultraviolet radiation.
It was first found in 1962 at Tugtup agtakôrfia Ilimaussaq intrusive complex of west Greenland. It has also been found at Mt Saint-Hilaire in Quebec and in the Lovozero Massif of the Kola Peninsula in Russia