Otjisumeite
A valid IMA mineral species
This page is currently not sponsored. Click here to sponsor this page.
About Otjisumeite
Formula:
PbGe4O9
Colour:
White, colorless
Lustre:
Greasy
Hardness:
3
Crystal System:
Triclinic
Name:
From Otjisume, the Herero name for Tsumeb, Namibia.
This page provides mineralogical data about Otjisumeite.
Unique Identifiers
Mindat ID:
3041
Long-form identifier:
mindat:1:1:3041:6
IMA Classification of Otjisumeite
Approved
IMA Formula:
Pb2+Ge4O9
Approval year:
1978
First published:
1981
Classification of Otjisumeite
9.J0.15
9 : SILICATES (Germanates)
J : Germanates
0 :
9 : SILICATES (Germanates)
J : Germanates
0 :
7.10.3.1
7 : MULTIPLE OXIDES
10 : AB4X9
7 : MULTIPLE OXIDES
10 : AB4X9
7.11.18
7 : Oxides and Hydroxides
11 : Oxides of Sn and Pb
7 : Oxides and Hydroxides
11 : Oxides of Sn and Pb
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Otj | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Otjisumeite
Optical Data of Otjisumeite
Type:
Biaxial (+)
RI values:
nα = 1.92 nβ = 1.922 nγ = 1.943
2V:
Measured: 20° , Calculated: 36°
Max. Birefringence:
δ = 0.023
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Moderate
Dispersion:
none
Chemistry of Otjisumeite
Mindat Formula:
PbGe4O9
Element Weights:
Elements listed:
Crystallography of Otjisumeite
Crystal System:
Triclinic
Cell Parameters:
a = 6.94 Å, b = 6.58 Å, c = 9.27 Å
α = 102.94°, β = 103.05°, γ = 114.77°
α = 102.94°, β = 103.05°, γ = 114.77°
Ratio:
a:b:c = 1.055 : 1 : 1.409
Unit Cell V:
349.32 ų (Calculated from Unit Cell)
Morphology:
Pseudohexagonal crystals
Elongated parallel to the c axis, columnar to fibrous habit; usually form radiating aggregates.
Elongated parallel to the c axis, columnar to fibrous habit; usually form radiating aggregates.
Comment:
Pseudo-hexagonal.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.87 Å | (30) |
| 4.20 Å | (40) |
| 3.41 Å | (50) |
| 2.95 Å | (100) |
| 2.41 Å | (30) |
| 2.26 Å | (30) |
| 2.22 Å | (50) |
| 1.847 Å | (40) |
| 1.782 Å | (40) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47h : [Near-surface oxidized, dehydrated minerals] |
Type Occurrence of Otjisumeite
Place of Conservation of Type Material:
Institute of Mineralogy and Crystal Chemistry of Stuttgart (FRG) University and at the Smithsonian Institution in Washington.
Associated Minerals at Type Locality:
Synonyms of Otjisumeite
Other Language Names for Otjisumeite
Common Associates
Associations Based on Photo Data:
| 10 photos of Otjisumeite associated with Plumbogummite | PbAl3(PO4)(PO3OH)(OH)6 |
| 4 photos of Otjisumeite associated with Galloplumbogummite | Pb(Ga,Al,Ge)3(PO4)2(OH)6 |
| 4 photos of Otjisumeite associated with Germanite | Cu13Fe2Ge2S16 |
| 3 photos of Otjisumeite associated with Chalcocite | Cu2S |
| 2 photos of Otjisumeite associated with Renierite | (Cu+,Zn)11Fe4(Ge4+,As5+)2S16 |
Related Minerals - Strunz-mindat Grouping
| 9.J0.05 | Carboirite | Fe2+Al2O(GeO4)(OH)2 |
| 9.J0.10 | Bartelkeite | Pb(Fe2+Ge)[Ge2O7](OH)2 · H2O |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Otjisumeite
mindat.org URL:
https://www.mindat.org/min-3041.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Otjisumeite
Localities for Otjisumeite
Showing 1 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Namibia (TL) | |
| Keller et al. (1981) |
Quick NavTopAbout OtjisumeiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesCommon AssociatesStrunz-MindatOther InformationInternet Links References Localities Locality List
Tsumeb Mine, Tsumeb, Oshikoto Region, Namibia