Murataite-(Y)
Murataite-(Y) is an IMA-recognized mineral species in the halide class, with the chemical formula (Y,Na)₆Zn(Zn,Fe³⁺)₄(Ti,Nb,Na)₁₂O₂₉(O,F,OH)₁₀F₄.
It crystallizes in the cubic crystal system (space group F-43m).
Key properties: Mohs hardness 5–6.5; specific gravity 4.5–4.69; Submetallic luster.
IMA symbol Mrat-Y, IMA status: approved, named in 1972.
Found as a rare accessory mineral in samples from the dump of a prospect in a pegmatite subjected to alkali metasomatism (St. Peters Dome, Colorado, USA); in pegmatite in a differentiated alkalic massif (Burpala massif, Russia).
It is found associated with Quartz, astrophyllite, microcline, albite, riebeckite, chlorite, zircon, aegirine, anatase, rutile, thorite, pyrochlore, xenotime, genthelvite.
The mineral was named to honor Kiguma Jack Murata (1909–), geochemist, U.S. Geological Survey, Menlo Park, California, USA, for his work on rare-earth chemistry.