Zektzerite

Zektzerite
General
Category	Mineral (Inosilicate)
Chemical formula	LiNa(Zr,Ti,Hf)Si6O15
Identification
Molar mass	529.66 g
Color	Colorless to pink, cream, or white; commonly zoned
Crystal habit	Stout pseudohexagonal prisms
Crystal system	Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: C mca
Cleavage	{100} and {010} perfect
Mohs scale hardness	6
Luster	Vitreous to pearly
Streak	White
Diaphaneity	Translucent to transparent
Specific gravity	2.79
Optical properties	Biaxial (-)
Refractive index	nα = 1.582 nβ = 1.584 nγ = 1.584
Ultraviolet fluorescence	Light yellow
References

The mineral zektzerite is a member of the tuhualite group and was first found in 1966 from the Willow creek basin below Silver Star mountain in miarolitic cavities within the alkaline riebeckite granite phase of the Golden Horn batholith, Okanogan County, Washington. It is named for Jack Zektzer (1936-), mathematician and mineral collector of Seattle, Washington.

The mineral was misidentified as alkali beryl (morganite) at that time. Subsequently in September, 1975 additional specimens of the mineral were found in a float boulder on the north side of Kangaroo Ridge at an approximate elevation of 6500 feet and recognized that the material was not beryl.

Properties

Synthesis: by fusion of Li₂CO₃, Na₂CO₃, SiO₂, ZrO₂. The resulting material has a brilliant blue white fluorescence under short wave ultraviolet light.^{[citation needed]}

Occurrence

A mineral of agpaitic (peralkaline, arfvedsonite) granites occurring with smoky quartz, microcline, arfvedsonite, okanoganite, sogdianite, astrophyllite, zircon. Found in cavities as euhedral crystals in the agpaitic granite phase of the Golden Horn batholith, Okanogan County Washington. It also occurs in blocks of pegmatite as rock forming grains in a moraine of the Dara Pioz glacier northern Tajikistan and as rock forming grains in the Del Salto pluton Aisen, Chile

References

• Die Seltene Mineralien von Dara-i-Pioz in Hochgebirge Tadshikistans Lapis v. 16(12) p. 42-48 (1991)
• Peralkaline rocks in the late Cretaceous Del Salto pluton Eastern Patagonian Andes Aisen Chile Revista Geologica de Chile v. 29 #1 July 1992 p. 3-15
• Glasser, F. P., Marr J. Synthesis of anhydrous silicates containing double chain anions Si6O15 (6-): Proceedings British Ceramic Society No. 28 p. 73-89 June 1979

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