Green elongated tabular vitreous crystals with dull luster of the extremely rare telluromandarinoite (IMA 2011-13) from the second known locality for the mineral, in an analyzed specimen by SEM/EDS and XRD, from Moctezuma (San Miguel Mine, Moctezuma, Moctezuma Municipality, Sonora, Mexico). — Photo: David Hospital · CC BY-SA 4.0
Telluromandarinoite
Telluromandarinoite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Fe³⁺₂(Te⁴⁺O₃)₃·6H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/c). It is a member of the Mandarinoite structural group.
Key properties: specific gravity 3.372; White streak; Vitreous luster; optically biaxial.
IMA symbol Tmda, IMA status: approved, named in 2011.
Of epithermal hydrothermal origin, found in the interstices of silicified dacitic tuff breccia.
It is found associated with Emmonsite, mackayite, poughite, rodalquilarite, two new unnamed Fe-tellurite minerals, alunite, barite, “silica”.
By a prefix, the name indicates the Te4+ (tellurium) analogue of mandarinoite.