The chemical formula of Meta-Autunite is indicated by Ca(UO2)2(PO4)2 – 2-6H2O or Hydrated Calcium Uranyl Phosphate. This Meta-Autunite is actually Phosphate mineral. It is most commonly used as mineral specimen and it is often found exhibiting splendid microscope images when viewed with the aid of polarizing microscope used in optical mineralogy. Meta-Autunite is also a minor ore of uranium. Meta-Autunite is actually a dehydration product of mineral Autunite. Meta-Autunite was named after its close cousin Autunite. Mineral Autunite converts into MetaAutunite when it losses water. Thus, it becomes a pseudomorph. In optical mineralogy, a pseudomorph is generally an atom by atom replacement of one mineral’s chemistry in replacement of another. It should be noted that the outward appearance remain largely unchanged. The process is then leaving the crystal shape of the original mineral intact, but the original mineral is no longer there. Pseudomorph means false shape. It was first found at Daybreak Mine, Washington, USA in 1904.
Meta-Autunite is a highly fluorescent mineral. It is commonly found exhibiting a bright fluorescence comparable to the brightest fluorescent mineral in the world. It is most commonly found exhibiting a bright green fluorescent color. The fluorescence of Meta-Autunite is due to its uranium content. Traces of uranium are responsible for the green flurescence displayed by opal as well as adamantine. It is also important to note that the Meta-Autunite is a radioactive mineral and it should be stored away from other minerals that are affected by radioactivity and human exposure should always be limited.
Mineral Meta-Autunite is most commonly found displaying lemon-yellow, greenish yellow, to canary yellow that could be more fascinating when viewed with the aid of petrographic polarizing microscope used in optical mineralogy. It can also sometimes be found with a black core, possibly due to uraninite. Meta-Autunite is also found exhibiting vitreous or pearly to dull luster when viewed in reflected light of polarizing microscope for mineralogists. Crystals of Meta-Autunite are also most commonly found translucent to opaque in appearance. Mineral Meta-Autunite is known to crystallize in the tetragonal system of crystal formation. In the field of optical mineralogy, this tetragonal system comprises crystals having three axes, which are all in a position perpendicular to one another. Two axes are usually found having the same or equal length.
The crystal habit of mineral Meta-Autunite as described in the field of optical mineralogy includes tabular square crystals dominated by two pinacoid faces. Crystals can actually look cubic as well as pseudocubic. Meta-Autunite can also be found in crusts form, micaceous, foliated, and earthy. Many crystals may actually pseudomorph Autunite. Meta-Autunite is most commonly found with perfect cleavage in one direction, which can be seen more clearly exhibited when viewed with the aid of petrographic polarizing microscope. Meta-Autunite is also most commonly found showing uneven fracture when viewed under polarized microscope use din optical mineralogy. The hardness measure of the mineral when it is evaluated using the Mohs scale method is usually found ranging from 2 to 2.5. The specific gravity measure of the mineral Meta-Autunite is approximately 3.5 grams per cubic centimeters to 3.6 grams per cubic centimeters, which is above average for translucent minerals and higher than Autunite due to loss of water molecules. Meta-Autunite is most commonly found leaving a pale yellow streak when rubbed on a white porcelain streak plate. Mineral Meta-Autunite is brightly fluorescent green to yellow green. This mineral is radioactive as mentioned earlier. The cleavage sheets are surprisingly brittle. Meta-Autunite is most commonly found exhibiting a uniaxial negative figure when viewed between crossed nicols of polarized microscope used in the field f optical mineralogy. It also shows moderate surface relief when viewed under several adjustments on the aperture diaphragm of the polarizing microscope for mineralogist. The best field indicators of Meta-Autunite include color, crystal habit, and higher density than Autunite, radioactivity, fluorescence, cleavage, and association. Mineral Meta-Autunite is most commonly found associated with other minerals including limonite, quartz, pyrite, autunite, torbernite, uraninite, and many other uranium minerals. Meta-Autunite notably occurs at several other localities including some areas in USA such as Arizona and California. It can be also found in England, Germany, and Australia.
