Outstanding yellow vitreous crystals of the extremely rare REE mineral moydite-(Y) from the type and only known locality worldwide in Canada; Evans-Lou Mine, Lac Saint-Pierre, Val-des-Monts, Outaouais, Québec, Canada. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Moydite-(Y)
Moydite-(Y) is an IMA-recognized mineral species in the carbonate class, with the chemical formula YB(OH)₄(CO₃).
It crystallizes in the orthorhombic crystal system (space group Pbca).
Key properties: specific gravity 3.13; Vitreous luster; optically biaxial.
IMA symbol Moy-Y, IMA status: approved, named in 1985.
Found as a rare secondary mineral in quartz in a zoned granite pegmatite.
It is found associated with Hellandite, kainosite, lokkaite, caysichite, xenotime, titanite, yttrian fluorapatite, yttrian spessartine, fergusonite, metatyuyamunite, metatorbernite, quartz.
The mineral was named to honor Louis Moyd (1916–), Canadian mineralogist, Emeritus Curator, National Museum of Natural Sciences, Ottawa, Canada, for his contributions to mineralogy.