Ilyukhinite
A very rare hydronium-bearing eudialyte-group mineral with cyclic silicate rings.
Intro adapted from Wikipedia (CC BY-SA).
Ilyukhinite is an IMA-recognized mineral species in the silicate class, with the chemical formula (H₃O,Na)₁₄Ca₆Mn₂Zr₃Si₂₆O₇₂(OH)₂·3H₂O.
It crystallizes in the hexagonal crystal system (space group R3m). It is a member of the Eudialyte structural group.
Key properties: Mohs hardness 5; specific gravity 2.67; White streak; Vitreous luster; optically uniaxial.
IMA symbol Ily, IMA status: approved, named in 2015.
Found in hydrothermally-altered peralkaline pegmatite.
It is found associated with Aegirine, murmanite, albite, microcline, rhabdophane-(Ce), fluorite, sphalerite, molybdenite.
The mineral was named to honor Russian crystallographer Vladimir Valentinovich Ilyukhin (1934-1982).