Zektzerite
- IMA 1976-034
The mineral Zektzerit is a very rarely occurring chain silicate from the Tuhualith group. It crystallizes in the orthorhombic crystal system with the chemical composition NaLiZr [ Si6O15 ] and usually develops well-developed crystals with pseudohexagonalem, tafeligem to prismatic habit, from white to pale pink color with white stroke color.
Etymology and history
Was first discovered Zektzerit the " Washington Pass " at Golden Horn in Okanogan County, Washington. First described in 1977 by Pete J. Dunn, Roland C. Rouse, Bart Cannon and Joseph A. Nelen who named the mineral after Jack Zektzer (* 1936), which provided scientists the mineral for their research available.
Classification
In the now outdated but still in use 8th edition of the mineral classification by Strunz the Zektzerit belonged to the mineral class of " silicates and Germanates " and then to the Department of " chain silicates and phyllosilicates ( inosilicates ) " where he along with Pellyit and Tuhualith an independent group formed.
The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification assigns the Zektzerit also in the class of " silicates and Germanates " and there in the department of " chains and chain silicates ( inosilicates ) " one. This division, however, is further subdivided according to the type of chain formation, so that the mineral is found in accordance with its construction in the subsection " chain and chain silicates with 6- periodic double chains ", where it together with Emeleusit and Tuhualith the unnamed group 9.DN .05 forms.
The classification of minerals according to Dana assigns the Zektzerit in the class of " silicates and Germanates " there, however in the department of " chain silicates: Double unbranched chains, W = 2". Here he is with Tuhualith and Emeleusit in the " Tuhualithgruppe P = 6 " with the system no. 66.03.04 within the subdivision " chain silicates: Double unbranched chains, W with chains P = 2 > 2 " to find.
Education and Locations
Zektzerit forms as a rare crystal filling in " Miarolen ", ie small cavities within granites or pegmatites, where it is usually found in paragenesis with aegirine, Astrophyllith, Elpidite, microcline, quartz, riebeckite or zirconium.
Except at its type locality " Washington Pass " at Golden Horn in Okanogan County ( Washington) in the U.S., the mineral has been able (as of 2011) yet in Darai - Pioz the Altay Mountains in Tajikistan and Del Salto in the Chilean province Aisen be found.
Crystal structure
Zektzerit crystallizes in the orthorhombic space group ( Raumgruppen-Nr. 64) with the lattice parameters a = 14.33 Å; b = 17.35 Å and c = 10.16 Å, and eight formula units per unit cell.
Use
For a useful as a raw material or semi-precious stone Zektzerit is too rare and due to its perfect cleavage and too sensitive. Occasionally he is but ground collectors in various forms.