Brown resinous crystals of the very rare yttrium mineral tritomite-(Y) from Cardiff Uranium Mine, Cardiff Township, Haliburton County, Ontario, Canada. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Tritomite-(Y)
Tritomite-(Y) is an IMA-recognized mineral species in the silicate class, with the chemical formula Y₅(SiO₄,BO₄)₃(O,OH,F).
It is a member of the Apatite structural group.
Key properties: Mohs hardness 3.5–6.5; specific gravity 3.05–3.4; Greenish gray streak; Weakly vitreous to resinous luster.
IMA symbol Tto-Y, IMA status: approved, named in 1961.
Found in granite pegmatites and pegmatite veins cutting pyroxenite.
It is found associated with Calcite, apatite, diopside, fluorite, scapolite (Cardiff township, Canada); albite, calcite, arfvedsonite, pyrite, quartz, tourmaline (Faraday mine, Canada).
The name refers to its relation to tritomite-(Ce), and yttrium in the composition.