Duttonite
Duttonite is an IMA-recognized mineral species in the vanadate class, with the chemical formula V⁴⁺O(OH)₂.
It crystallizes in the monoclinic crystal system (space group I2/c).
Key properties: Mohs hardness 2.5; specific gravity 3.24; Vitreous luster; optically biaxial.
IMA symbol Dtn, grandfathered status — known before the IMA’s founding, named in 1956.
A secondary mineral formed by the low-temperature hydrothermal alteration of vanadium-bearing minerals.
It is found associated with Melanovanadite, lenoblite, selenium, simplotite, montroseite, paramontroseite, uraninite, coffinite (Peanut mine, Colorado, USA); hewettite, fervanite.
The mineral was named to honor Captain Clarence Edward Dutton (1841–1912), American geologist with the U.S. Geological Survey, an early worker on the Colorado Plateau.