Tullerite

Tullerite is a mineral with the chemical formula Ca3Zr2(SiO4)2(OH)2. It is a member of the silicate mineral group, specifically belonging to the sorosilicate subclass. Tullerite is characterized by the presence of isolated [SiO4]4- tetrahedra, which are linked together by calcium and zirconium ions, along with hydroxyl groups. Its crystal structure is monoclinic.

The mineral was first described in 1985 and named in honor of Professor Paul Tuller, a geologist at the University of Bern. Tullerite is found in metamorphic rocks, particularly those that have undergone high-grade metamorphism. It typically occurs in association with other calcium and zirconium-bearing minerals.

Tullerite is relatively rare and has been documented in only a few locations worldwide. Notable occurrences include the Khibiny Massif in Russia and certain metamorphic terrains in Norway and Greenland. The geological conditions required for its formation are quite specific, involving elevated temperatures and pressures.

Physically, tullerite is typically found as small, translucent to opaque crystals. Its color can range from colorless to white or pale gray. It is a relatively hard mineral, with a Mohs hardness of approximately 5.5. Due to its rarity and the specific conditions under which it forms, tullerite is of interest to mineralogists studying metamorphic petrology and the behavior of elements in geological environments.