Dagenaisite, A New Zinc Tellurate From the Gold Chain Mine, Tintic, Utah, U.S.A.
Abstract
Dagenaisite, Zn_3Te^(6+)O_6, is a new mineral from the Gold Chain mine, Tintic district, Juab County, Utah, U.S.A. It is a late-stage secondary phase formed by the oxidative alteration of earlier Te- and Zn-bearing minerals. It is associated with cinnabar, dugganite, eurekadumpite, and gold in vugs in a matrix composed of quartz and dolomite. The mineral occurs as tiny light greenish-gray platelets, generally intermixed with amorphous material, forming porous masses that are apparently replacements of earlier phases. The streak is white, the luster is pearly, and crystals are transparent to translucent. The hardness could not be measured, but appears to be <2 (Mohs). The tenacity is flexible, the fracture is irregular, and cleavage was not observed. The calculated density is 6.00 g/cm^3 for the empirical formula. At room temperature, the mineral is slowly soluble in dilute HCl and rapidly soluble in concentrated HCl. Optical properties could not be determined. Electron-microprobe analyses gave the empirical formula (Zn_(2.39)Cu_(0.36)Ca_(0.06)Mn_(0.03)As_(0.03)Si_(0.02))_(Σ2.89)Te_(1.02)O_6. The mineral is monoclinic, space group C2/c, with cell parameters a 14.87(2), b 8.88(2), c 10.37(2) Å, β 93.33(2)°, V 1367(4) Å^3, and Z = 12. The five strongest lines in the X-ray powder diffraction patterns are [d_(obs) Å(I)(hkl)]: 4.311(30)(310), 3.029(44)(222), 2.744(68) (313, 421), 2.539(100) (132, 422), and 1.6568(48) (732, 350, 244). The mineral is the natural counterpart of synthetic Zn_3Te^(6+)O_6, which has a structure based on an approximate close packing of O atoms in an hhchhc sequence along [100].
Additional Information
© 2017 Mineralogical Association of Canada. Received May 26, 2017. Revised manuscript accepted July 24, 2017. Reviewers Stuart Mills and Andrew Christy are thanked for their constructive comments on the manuscript. The microprobe analyses were funded by a grant to Caltech from the Northern California Mineralogical Society. The rest of this study was funded by the John Jago Trelawney Endowment to the Mineral Sciences Department of the Natural History Museum of Los Angeles County.Additional details
- Eprint ID
- 82277
- DOI
- 10.3749/canmin.1700037
- Resolver ID
- CaltechAUTHORS:20171011-092732591
- Northern California Mineralogical Society
- John Jago Trelawney Endowment
- Created
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2017-10-11Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field