Jeffreyite
Jeffreyite is an IMA-recognized mineral species in the silicate class, with the chemical formula (Ca,Na)₂(Be,Al)Si₂(O,OH)₇.
It crystallizes in the orthorhombic crystal system (space group C222_1). It is a member of the Melilite structural group.
Key properties: Mohs hardness 5; specific gravity 2.99; optically biaxial.
IMA symbol Jfy, IMA status: approved, named in 1982.
Found in a cavity in a highly calcium-metasomatized granite dike.
It is found associated with Grossular.
The name is taken from the type locality, the Jeffrey mine, Quebec, Canada.
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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