Cayalsite-(Y)
Cayalsite-(Y) is an IMA-recognized mineral species in the silicate class, with the chemical formula CaY₆Al₂Si₄O₁₈F₆.
It crystallizes in the orthorhombic crystal system (space group Pban).
Key properties: Mohs hardness 6.5; White streak; Vitreous luster; optically biaxial.
IMA symbol Cyl-Y, IMA status: approved, named in 2011.
A late-stage mineral in cavities in yttrian fluorite in granitic NYF-pegmatite.
It is found associated with Bastnäsite-(Ce), hematite, vyuntspakhkite-(Y), hundholmenite-(Y).
The name comes from the chemical symbols for the essential elements in the mineral (Ca-Y-Al-Si) and a suffex for the dominant rare-earth element.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
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