- Metazeunerite
-
Metazeunerite 
Metazeunerite crystals to 7 mm on smoky quartz, Erongo Region, NamibiaGeneral Category Phosphate minerals Chemical formula Cu(UO2)2(AsO4)2·8H2O Strunz classification 08.EB.10 Crystal symmetry Tetragonal dipyramidal
H-M symbol: 4/m
Space group: P42/nUnit cell a = 7.1094 Å, c = 17.416 Å;
Z = 2Identification Color Varies from pale to green Crystal habit Tabular rectangular crystals with two pinacoid faces; foliated or micaceous aggregates Crystal system Tetragonal Twinning Merohedrally twinned Cleavage Perfect on {001}; distinct on {010} Fracture Uneven Tenacity Brittle Mohs scale hardness 2-2.5 Luster Vitreous to dull Streak Pale green Diaphaneity Transparent to translucent Specific gravity 3.87 Optical properties Uniaxial(-) Refractive index nw=1.643-1.651 nε=1.623-1.635 Birefringence .020 Pleochroism Weak Other characteristics Radioactive References [1][2] Metazeunerite is an arsenate mineral with a chemical formula of Cu(UO2)2(AsO4)2·8H2O. The origin of this mineral comes from the dehydration process that metazeunerite must go through, and it’s association with zeunerite. As dehydration occurs, zeunerite loses an electron and is then metamorphosed into metazeunerite.[3] Its crystal system is tetragonal and its crystal class is 4/m, which is also called the tetragonal-dipyramidal class because it only has a vertical four-fold rotation axis that is perpendicular to the symmetry plane.[4][5] When looking at a thin section, metzeunerite is anisotropic, meaning that it has pleochroism. When a mineral is anisotropic, one can see whether it is unaixial or biaxial, depending on how fast the rays of light are moving through the mineral. This mineral is uniaxial negative due to the ordinary ray being slower than the extraordinary ray.[6]
Metazeunerite is an uncommon radioactive secondary mineral found in "arsenic bearing hydrothermal uranium deposits" across the world.[7] This widespread mineral occurs specifically in Europe, western North America, Australia, Brazil and Chili, Namibia, and Kazakhstan.[2] It is currently studied through thermal decomposition by calculating the different levels of dehydration, as zeunerite is transformed into metazeunerite.[8]
References
- ^ Metazeunerite Mineral Data Webmineral
- ^ a b Metazeunerite on Mindat
- ^ Amethyst Galleries
- ^ Roberts,W., Campbell,T., and Rapp,G. (1990) Encyclopedia of Minerals (Second Edition), 558 p. Van Nordstrand Reinhold, New York.
- ^ Klein, C., and Dutrow, B. (2007) The 23rd Edition of the Manual of Mineral Science (23rd edition), 194 p. John Wiley & Sons, Inc.
- ^ "Optical Properties of Minerals." University of North Dakota
- ^ "Metazeunerite." Mineral Data Publishing, 2005
- ^ Frost, Ray L. "ScienceDirect - Thermochimica Acta : Thermal Decomposition of Metazeunerite—a High-resolution Thermogravimetric and Hot-stage Raman Spectroscopic Study." ScienceDirect - Home. Queensland University of Technology, 9 Apr. 2004. Web. 22 Nov. 2010
Categories:- Arsenate minerals
- Copper minerals
- Uranium minerals
- Tetragonal minerals
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