Quadruphite
Quadruphite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₆Na₂(CaNa)₂Na₂Ti₂Na₂Ti₂(Si₂O₇)₂(PO₄)₄O₄F₂.
It crystallizes in the triclinic crystal system (space group P1). It is a member of the Seidozerite-Murmanite structural group.
Key properties: Mohs hardness 5; specific gravity 3.12; White streak; Vitreous, resinous on fractures, pearly to adamantine on cleavages. Streak: White luster; optically biaxial.
IMA symbol Qua, 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, polyphite, lomonosovite.
The name comes from the Latin quadruplex, for four, and PHosphorus, for the four phosphate anions in the chemical formula.