Mianningite
Mianningite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula ( ,Pb,Ce,Na)(U⁴⁺,Mn,U⁶⁺)Fe³⁺₂(Ti,Fe³⁺)₁₈O₃₈.
It crystallizes in the hexagonal crystal system (space group R-3). It is a member of the Crichtonite structural group.
Key properties: Mohs hardness 6; specific gravity 4.62; Black streak; Submetallic luster.
IMA symbol Min, IMA status: approved, named in 2014.
Found in fractures within lamprophyre veins and their contacts with a later quartz-alkali feldspar syenite dike containing REE, U, and Th mineralization.
It is found associated with Microcline, albite, quartz, iron-rich phlogopite, augite, muscovite, calcite, barite, fluorite, epidote, magnetite, hematite, galena, hydroxylapatite.
The name refers to the county in China that provided the first specimens.