Umohoite

Umohoite
General
Category	Oxide and Hydroxide
Formula (repeating unit)	(UO2)MoO4·2H2O
IMA symbol	Umo[1]
Crystal system	Triclinic
Identification
Color	Black, blue-black, dark green, orange-red [2]
Cleavage	Perfect on {001}
Mohs scale hardness	2
Luster	Vitreous
Streak	Blue gray
Diaphaneity	Opaque
Density	4.53 - 4.66 g/cm3 (Measured) 4.49(3) g/cm3 (Calculated)
Refractive index	nα = 1.660 nβ = 1.831 nγ = 1.915
2V angle	Measured: 65°, Calculated: 64°
Other characteristics	Radioactive

Umohoite is a rare oxide and hydroxide mineral. The name of this mineral reflects its composition: uranyl (U), molybdate (Mo) and water (H₂O). Its chemical formula is (UO₂)MoO₄·2H₂O.[3]

Umohoite's type location is in Marysvale, the mineral was first described by Paul F. Kerr and G. P. Brophy in 1953.[4]

References

1. Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
2. F. Dal Bo, F. Hatert, S. Philippo (2018). "Supergene Uranyl Mineralization of the Rabejac Deposit, Lodève, France." Minerals, Volume 8, Issue 9.
3. "Umohoite: Umohoite mineral information and data". mindat.org. Retrieved 2019-08-14.
4. Brophy, G.P. & Kerr, P.F. (1953): Hydrous uranium molybdate in Marysvale ore. Annual Report June 30, 1952 - April 1, 1953 U.S.Atomic Energy Comm., RME-3046, 45-51.