divided OD uraninite
into four groups based on textural and compositional characteristics.
The data points bracket the stability field boundary between uraninite
and uranyl-hydroxide complexes.
Moreover, there are also rhenium occurrences associated with uraninites
(c) Grape-like uraninite
imbedded in stacks of micritic kaolinite.
The mineral was identified as uraninite
(radioactive, uranium rich mineral) the overall chemical composition of which is represented as UO2.
Autunite and torbernite were the only minerals found in fine specimens, although uraninite
and phosphuranylite were also reported.
Recent work including dating of pure secondary uranium phases at Palmottu and another nearby site clearly indicate postglacial mobilization of uranium from primary (mainly uraninite
) and secondary uranium phases (uranophane) in open fractures and the rock matrix and redeposition as uranophane after very short travel distances downwards (scale of meters) (Read et al., 2004)
The HREE enrichment in episyenites can be explained by the formation of HREE-bearing uranium minerals (coffinite, uraninite
; Cathelineau, 1987; Fayek and Kyser, 1997).
G5 is a sample of the CMG which is a light pink, medium-to coarse-grained alkali feldspar granite containing, on average, 38% quartz, 33% orthoclase, 27% albite (~An5), and 2% biotite with accessory apatite, zircon, monazite, uraninite
The Leningrad institute explained the surprisingly uniform distribution of element A-9 between the separable components of the Estonian black shale by the possible presence of A-9 in the form of extremely small particles of a heavy oxide mineral, such as uraninite
Nayak, "Genetic implications of rare uraninite
and pyrite in quartz-pebble conglomerates from Sundargarh District of Orissa, Eastern India," Journal of the Geological Society of India, vol.
The uranium mineral is primarily uraninite
, and where present at grades of greater than 500 ppm, is marked by the presence of significant visible smokey quartz and, frequently, biotite.