Tsaregorodtsevite Locality: Yaruta Mt, Man'-Khambo Mts, Khanty-Mansi (Khanty Mansiysk) Okrug, Polar Urals, Western-Siberian Region, Russia ( Locality at mindat.org ) Size: miniature, 6 x 3.7 x 1.8 cm Tsaregorodtsevite Tsaregorodtsevite is a VERY STRANGE mineral that is made up of AMMONIA with nitrogen, and an aluminosilicate compound. I recall when Fersman Museum started selling their extras in 1991, this was one of the most coveted of all rare species that came out the doors from their various expeditions. I got some directly at the time from curator Dmitriy Belakovskiy, who has himself been to this remote location on at least one expedition. I assume this specimen came form teh same source, the only source so far as I know. I have owned several over the years, and I can say this is a very good and rich specimen. It has crystals to 4mm. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Tsaregorodtsevite
Tsaregorodtsevite is an IMA-recognized mineral species in the organic mineral class, with the chemical formula N(CH₃)₄Si₄(SiAl)O₁₂.
It crystallizes in the orthorhombic crystal system (space group I222). It is a member of the Cancrinite-sodalite, Sodalite structural group.
Key properties: Mohs hardness 6; specific gravity 2.04; White streak; Vitreous luster; optically biaxial.
IMA symbol Tsa, IMA status: approved, named in 1991.
Found in friable material filling tectonic fractures in muscovite-chlorite schist.
It is found associated with Chlorite, quartz, anatase, brookite, rutile, monazite, phillipsite, albite.
The name refers to Sergei Vasil'evich Tsaregorodtsev (1953–1986), Yekaterinberg (Sverdlovsk), Russia, expert collector of Uralian minerals, who found this mineral.