Polyphite
Polyphite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₆(Na₄Ca₂)₂Na₂Ti₂Na₂Ti₂(Si₂O₇)₂(PO₄)₆O₄F₄.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Seidozerite-Murmanite structural group.
Key properties: Mohs hardness 5; specific gravity 3.07; White streak; Vitreous, resinous on fractures, pearly to adamantine on cleavages. Streak: White luster; optically biaxial.
IMA symbol Ppt, IMA status: approved, named in 1990.
Found in ultra-agpaitic pegmatites in a differentiated alkalic massif.
It is found associated with Nepheline, sodalite, analcime, potassic feldspar, albite, arfvedsonite, aegirine, cancrisilite, ussingite, makatite, villiaumite, quadruphite, lomonosovite.
Its name comes from the Greek poly, for many, and PHosphorus, for the multiple phosphate anions in the chemical formula.