Umohoite Explained

Umohoite
Category:	Oxide and Hydroxide
Formula:	(UO2)MoO4·2H2O
Imasymbol:	Umo^[1]
Color:	Black, blue-black, dark green, orange-red ^[2]
System:	Triclinic
Cleavage:	Perfect on
Mohs:	2
Luster:	Vitreous
Streak:	Blue gray
Diaphaneity:	Opaque
Density:	4.53 - 4.66 g/cm3 (Measured) 4.49(3) g/cm3 (Calculated)
Refractive:	nα = 1.660 nβ = 1.831 nγ = 1.915
2V:	Measured: 65°, Calculated: 64°

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

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

Notes and References

1. Warr. L.N.. 2021. IMA–CNMNC approved mineral symbols. Mineralogical Magazine. 85. 3. 291–320. 10.1180/mgm.2021.43. 2021MinM...85..291W. 235729616. free.
2. F. Dal Bo, F. Hatert, S. Philippo (2018). "Supergene Uranyl Mineralization of the Rabejac Deposit, Lodève, France." Minerals, Volume 8, Issue 9.
3. Web site: Umohoite: Umohoite mineral information and data.. mindat.org. 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.