White crystals of the extremely rare and relatively new mineral (IMA 2007-008) andrianovite from the type and only known locality worldwide: Koashva Mountain, Khibiny Massif, Kola, Russian Federation. — Photo: David Hospital · CC BY-SA 4.0
Andrianovite
A very rare eudialyte-group mineral whose complex formula packs in sodium, potassium, strontium, cerium, calcium, manganese, iron, zirconium and niobium.
Intro adapted from Wikipedia (CC BY-SA).
Andrianovite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₁₂(K,Sr,Ce)₃Ca₆Mn₃Zr₃Nb(Si₂₅O₇₃)(O,H₂O,OH)₅.
It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Eudialyte structural group.
Key properties: Mohs hardness 5; specific gravity 2.93; White streak; Vitreous luster; optically uniaxial.
IMA symbol Adv, IMA status: approved, named in 2007.
Found in hyperperalkaline pegmatite in an alkaline massif.
It is found associated with Aegirine, sodalite, microcline, natrolite, lomonosovite, lamprophyllite, mosandrite, villiaumite.
The mineral was named to honor Valerii Ivanovich Andrianov (1938-1991), Russian mathematician and crystallographer.