Holfertite Locality: Holfertite pit, Starvation Canyon (Searles Canyon), Thomas Range, Juab Co., Utah, USA Field of view 2 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Holfertite
Holfertite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula (UO₂)₁.₇₅Ca₀.₂₅TiO₄·3H₂O.
It crystallizes in the hexagonal crystal system (space group P3).
Key properties: Mohs hardness 4; specific gravity 4.22; Pale yellow streak; Adamantine luster; optically uniaxial.
IMA symbol Hlf, IMA status: approved, named in 2003.
A pneumatolytic phase in rhyolite.
It is found associated with Hematite, bixbyite, fluorite, topaz, beryl, calcite.
The mineral was named to honor John W. Holfert (b. 1949) for his contributions to understanding the mineral occurrences in the Thomas Range, Utah, USA.