Hydropascoite
Hydropascoite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Ca₃(V₁₀O₂₈)·24H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Pascoite structural group.
Key properties: Mohs hardness 1.5; specific gravity 2.38; Pistachio-green streak; Vitreous luster; optically biaxial.
IMA symbol Hpas, IMA status: approved, named in 2016.
Found as a secondary mineral in an oxidized roll-front uranium and vanadium deposit in sandstone.
It is found associated with Asphaltum, montroseite, corvusite, pascoite, rossite/metarossite, sherwoodite.
Alludes to the compositional and structural similarity of the mineral to pascoite, Ca3(V10O28)·17H2O, and with a prefix for the fact that it has 41% more H2O groups.