Zektzerite

Infobox mineral
name = Zektzerite
category = Mineral (Inosilicate)
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formula = LiNa(Zr,Ti,Hf)Si₆O₁₅
molweight = 529.66 gm
color = Colorless to pink
habit =
system = Orthorhombic
twinning =
cleavage = {100} and {010} cleavages perfect
fracture =
tenacity =
mohs = 6
luster = Vitreous
polish =
refractive = nα = 1.582 nβ = 1.584 nγ = 1.584
opticalprop = Biaxial (-)
birefringence =
dispersion =
pleochroism =
fluorescence= light yellow
absorption =
streak = White
gravity = 2.79
density =
melt =
fusibility =
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solubility =
diaphaneity = Transparent
other =
references = [http://webmineral.com/data/Zektzerite.shtml Webmineral] [http://rruff.geo.arizona.edu/doclib/hom/zektzerite.pdf Mineral Handbook] [http://www.mindat.org/min-4390.html Mindat]

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 the agpaitic granite phase of the Golden Horn batholith, Okanogan County, Washington by Bart Cannon of Seattle, Washington. It is named for Jack Zektzer of Seattle, Washington who first recognized that the mineral was unknown.

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. The mineral was then referred to the Mineralogy Department of the Smithsonian Institution in November 1975 with subsequent publication by Pete Dunn et. al in the American Mineralogist. Zektzerite has been subsequently found in blocks of pegmatite as rock forming grains in a lateral moraine of the Dara Pioz glacier in northern Tajikistan and in the agpaitic granite of the Del Salto pluton Aisen, Chile as rock forming grains.

Properties

* Largest crystal reported: 3.7 cm.Synthesis: by fusion of Li₂CO₃, Na₂CO₃, SiO₂, ZrO₂. The resulting material has a brilliant blue white fluorescence under short wave ultraviolet light.

Occurrence

A mineral of agpaitic (peralkaline, arfvedsonite) granites occurring with smoky quartz, microcline, arfvedsonite, okanoganite, sogdianite, astrophyllite. Found in cavities as euhedral crystals in the agpaitic granite phase of the Golden Horn batholith, Okanogan County Washington at such places as the Silver Star viewpoint on Washington state route 20, the ridge above that lookout, Kangaroo Ridge, Willow Creek basin and the slopes of Silver Star Mountain. 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

* Dunn et al: Zektzerite: a new lithium sodium zirconium silicate related to tuhualite and the osumilite group American Mineralogist v. 62 p. 416-20 (1977)
* 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