Orthobrannerite

U4+U6+Ti4O12(OH)2
IMA status
  • Approved
  • Grandfathered
IMA symbol
Obnr
Discovered
1978
Also known as
  • Orthobranneriet
  • Orthobrannerita

Where it forms, where it's found

Geological setting

Weathering residue of a biotite pyroxene syenite in Yunan, China.

Type locality
Yunnan
  1. China
7recorded occurrences
Source · OpenStreetMap

Radioactivity

Physical

Hardness
123456789105.5/ 10 MOHS
  1. 1Talc
  2. 2Gypsum
  3. 3Calcite
  4. 4Fluorite
  5. 5Apatite
  6. 6Orthoclase
  7. 7Quartz
  8. 8Topaz
  9. 9Corundum
  10. 10Diamond
Transparency
Translucent
Colour
Black
Streak
Dark brown to black

Crystallography

Crystal system
Orthorhombic
Cell parameters
a = 7.37 Å · b = 11.67 Å · c = 6.33 Å
Ratio a:b:c
1 : 1.583 : 0.859
Morphology

Prismatic crystals, to 1.2 cm.

Comment

Cell obtained after heating completely metamict type material to 1000°C.

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
92UUraniumUranium2238.029476.058
53.28%
8OOxygenOxygen1415.999223.986
25.07%
22TiTitaniumTitanium447.867191.468
21.43%
1HHydrogenHydrogen21.0082.016
0.22%
Total893.528100.00%

Mass share = atoms × atomic mass ÷ molar mass × 100

From IMA formula

Synonyms

  • Orthobranneriet
  • Orthobrannerita

In other languages

German
Orthobrannerit
Italian
Orthobrannerite · Ortobrannerite

Classification

Strunz
10th ed.

4.DH.05

  • 4OxidesClass
  • 4.DMetal: Oxygen = 1:2 and similarDivision
  • 4.DHWith large (+- medium-sized) cations; sheets of edge-sharing octahedraGroup
  • 4.DH.05OrthobranneriteSpecies
Dana
8th ed.

08.02.07.01

  • 08Multiple Oxides Containing Niobium, Tantalum or TitaniumClass
  • 08.02A2B2O6(O,OH,F)Type
  • 08.02.07— unnamed intermediate level —Group
  • 08.02.07.01OrthobranneriteSpecies
CIM

7.16.19

  • 7Oxides and HydroxidesClass
  • 7.16Oxides of UGroup
  • 7.16.19OrthobranneriteSpecies

Literature, links & citation

Citations
  1. 1978X-ray Laboratory, Peking Institute of Uranium Geology and Xray Laboratory, Wuhan Geological College (1978) Orthobrannerite - A new mineral of the brannerite group. Acta Geologica Sinica: 52(3): 241-251 (in Chinese with English abstract). http://rruff.info/rruff_1.0/uploads/AGS52_241.pdf
  2. 1978X-ray Laboratory, Peking Institute of Uranium Geology and Xray Laboratory, Wuhan Geological College (1978) Orthobrannerite - A new mineral of the brannerite group. Acta Geologica Sinica: 52(3): 241-251.
  3. 1979Fleischer, Michael, Chao, George Y., Mandarino, J. A. (1979) New mineral names. American Mineralogist, 64 (5-6) 652-659
  4. 2005(2005) Orthobrannerite. Handbook of Mineralogy. Mineralogical Society of America
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Orthobrannerite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/orthobrannerite-3023},
  note      = {Accessed 2026-05-11}
}