Nuragheite | |
---|---|
General | |
Category | Molybdate minerals |
Formula (repeating unit) | Th(MoO4)2·H2O |
IMA symbol | Nur[1] |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | P21/c |
Unit cell | a = 7.36, b = 10.54 c = 9.49 [Å], β=91.88° (approximated) |
Identification | |
Color | Colorless |
Crystal habit | Thin tablets |
Cleavage | {100}, perfect |
Tenacity | Brittle |
Luster | Pearly adamantine |
Streak | White |
Specific gravity | 5.15 (calc., approximated) |
Other characteristics | Radioactive |
References | [2][3] |
Nuragheite is a rare[3] natural thorium molybdate, formula Th(MoO4)2·H2O, discovered in Su Seinargiu, Sarroch, Cagliari, Sardegna, Italy.[2] This locality is also a place of discovery of the other thorium molybdate - ichnusaite, which is a trihydrate.[4]
Nuragheite is a part of molybdenum-bismuth mineralization. It coexists with ichnusaite, muscovite, and xenotime-(Y).[2]
Nuragheite is chemically pure.[2]
The crystal structure of nuragheite is composed of (100) layers with IXTh-centered polyhedra and Mo-centered tetrahedra.[2] It is thus similar to that of ichnusaite.