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Jacobsite-Q
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About Jacobsite-Q
Formula:
Mn2+(Fe3+,Mn3+)2O4
From Bosi et al. (2018); type material has Fe3+:Mn3+ = 2:1.
Colour:
Greenish black, black
Lustre:
Sub-Vitreous, Metallic, Sub-Metallic
Hardness:
6 - 6½
Specific Gravity:
4.85
Crystal System:
Tetragonal
Member of:
First Recorded Locality:
Dimorph of:
Isostructural with:
A polymorph of jacobsite, termed jacobsite-Q, earlier named iwakiite.
Contains significant octahedrally coordinated Mn3+ distorting the crystal structure to tetragonal.
See also α-vredenburgite.
Contains significant octahedrally coordinated Mn3+ distorting the crystal structure to tetragonal.
See also α-vredenburgite.
Unique Identifiers
Mindat ID:
2058
Long-form identifier:
mindat:1:1:2058:5
Similar Names
| Jacobsite | A valid IMA mineral species - grandfathered | Mn2+Fe23+O4 |
IMA Classification of Jacobsite-Q
IMA status notes:
Redefined by the IMA, Renamed by the IMA
Approval history:
First described as iwakiite by Matsurbara et al. (1979). Redefined as the tetragonal polymorph of jacobsite and renamed as jacobsite-Q by IMA 2018 (Bosi et al. 2018).
Classification of Jacobsite-Q
7.2.6.2
7 : MULTIPLE OXIDES
2 : AB2X4
7 : MULTIPLE OXIDES
2 : AB2X4
7.9.14
7 : Oxides and Hydroxides
9 : Oxides of Ti
7 : Oxides and Hydroxides
9 : Oxides of Ti
Physical Properties of Jacobsite-Q
Sub-Vitreous, Metallic, Sub-Metallic
Transparency:
Opaque
Colour:
Greenish black, black
Comment:
May look completely black, may be iridescent due to surface alteration.
Streak:
Black
Hardness:
6 - 6½ on Mohs scale
Tenacity:
Brittle
Cleavage:
None Observed
None
None
Fracture:
Conchoidal, Sub-Conchoidal
Density:
4.85 g/cm3 (Measured) 4.89 g/cm3 (Calculated)
Optical Data of Jacobsite-Q
Reflectivity:
| Wavelength | R1 (%) |
|---|---|
| 20nm | 20 20.0 19.4440 19.9 19.3460 20.3 19.5480 20.4 19.6500 20.8 19.8520 21.2 20.1540 21.4 20.3560 21.3 20.4580 21.2 20.1600 21.0 20.0620 20.9 19.7640 20.5 19.6660 20.4 19.2680 20.2 19.1% |
Graph shows reflectance levels at different wavelengths (in nm). Peak reflectance is 20 20.0 19.4440 19.9 19.3460 20.3 19.5480 20.4 19.6500 20.8 19.8520 21.2 20.1540 21.4 20.3560 21.3 20.4580 21.2 20.1600 21.0 20.0620 20.9 19.7640 20.5 19.6660 20.4 19.2680 20.2 19.1%.
Colour in reflected light:
olive-gray
Internal Reflections:
none observed
Pleochroism:
Non-pleochroic
Chemistry of Jacobsite-Q
Mindat Formula:
Mn2+(Fe3+,Mn3+)2O4
From Bosi et al. (2018); type material has Fe3+:Mn3+ = 2:1.
From Bosi et al. (2018); type material has Fe3+:Mn3+ = 2:1.
Element Weights:
Elements listed:
Crystallography of Jacobsite-Q
Crystal System:
Tetragonal
Class (H-M):
4/mmm(4/m2/m2/m) - Ditetragonal Dipyramidal
Space Group:
I41/amd
Setting:
I41/amd
Cell Parameters:
a = 6.025 Å, c = 8.54 Å
Ratio:
a:c = 1 : 1.417
Unit Cell V:
310.01 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Rarely octahedral, usually granular
Twinning:
{101}, similar to hausmannite
Crystal Structure
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Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0010983 | Jacobsite-Q | Jarosch D (1988) Crystal structure of iwakiite Zeitschrift fur Kristallographie 185 605-605 |  | 1988 | Gozaisho mine, Fukushima Prefecture, Japan | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.929 Å | (30) |
| 3.016 Å | (40) |
| 2.570 Å | (100) |
| 2.461 Å | (6) |
| 2.135 Å | (16) |
| 2.130 Å | (16) |
| 1.739 Å | (15) |
| 1.640 Å | (30) |
| 1.509 Å | (35) |
| 1.506 Å | (40) |
| 1.299 Å | (10) |
| 1.284 Å | (8) |
Comments:
Satoshi MATSUBARA, Akira KATO, Kozo NAGASHIMA (1978) Mineralogical Magazine, v9, pp.383-391.
First Recorded Occurrence of Jacobsite-Q
Associated Minerals at First Recorded Locality:
Synonyms of Jacobsite-Q
Other Language Names for Jacobsite-Q
Relationship of Jacobsite-Q to other Species
Member of:
Other Members of Spinel Subgroup:
| Chihmingite | NiAl2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Chromite | Fe2+Cr3+2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Cochromite | CoCr2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Coulsonite | Fe2+V3+2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Cuprospinel | Cu2+Fe3+2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Dellagiustaite | V2+Al2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Deltalumite | (Al0.67◻0.33)Al2O4 | Tet. 42m : P4m2 |
| Franklinite | Zn2+Fe3+2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Gahnite | ZnAl2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Galaxite | Mn2+Al2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Guite | Co2+Co3+2O4 | Iso. |
| Hausmannite | Mn2+Mn3+2O4 | Tet. 4/mmm(4/m2/m2/m) : I41/amd |
| Hercynite | Fe2+Al2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Hetaerolite | ZnMn2O4 | Tet. 4/mmm(4/m2/m2/m) : I41/amd |
| Jacobsite | Mn2+Fe3+2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Maghemite | (Fe3+0.67◻0.33)Fe3+2O4 | Iso. 432 : P4132 |
| Magnesiochromite | MgCr2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Magnesiocoulsonite | MgV2O4 | Iso. m3m(4/m32/m) |
| Magnesioferrite | MgFe3+2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Magnetite | Fe2+Fe3+2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Manganochromite | Mn2+Cr2O4 | Iso. m3m(4/m32/m) : Fd3m |
| 'Nichromite' | (Ni,Co,Fe)(Cr,Fe,Al)2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Spinel | MgAl2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Thermaerogenite | CuAl2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Titanomaghemite | (Ti4+0.5◻0.5)Fe3+2O4 | Iso. 432 : P4332 |
| Trevorite | Ni2+Fe3+2O4 | Iso. m3m(4/m32/m) : Fd3m |
| 'UM1994-06-O:AlCo' | CoAl2O4 | |
| Vuorelainenite | Mn2+V3+2O4 | Iso. m3m(4/m32/m) : Fd3m |
| Zincochromite | ZnCr2O4 | Iso. m3m(4/m32/m) : Fd3m |
Common Associates
Associations Based on Photo Data:
| 2 photos of Jacobsite-Q associated with Spessartine | Mn2+3Al2(SiO4)3 |
| 1 photo of Jacobsite-Q associated with Jacobsite | Mn2+Fe3+2O4 |
| 1 photo of Jacobsite-Q associated with Diopside | CaMgSi2O6 |
| 1 photo of Jacobsite-Q associated with Rhodonite | CaMn3Mn[Si5O15] |
| 1 photo of Jacobsite-Q associated with Calcite | CaCO3 |
| 1 photo of Jacobsite-Q associated with 'Manganophyllite' | K(Fe,Mg,Mn)3AlSi3O10(OH)2 |
| 1 photo of Jacobsite-Q associated with Adelite | CaMg(AsO4)(OH) |
Fluorescence of Jacobsite-Q
Not fluorescent in UV
Other Information
Magnetism:
Ferrimagnetic
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 Jacobsite-Q
mindat.org URL:
https://www.mindat.org/min-2058.html
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Please feel free to link to this page.
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References for Jacobsite-Q
Localities for Jacobsite-Q
Showing 13 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.
Austria | |
| Kolitsch et al. (2017) |
Japan (FRL) | |
| Matsubara et al. (1979) +3 other references |
Romania | |
| Udubasa et al. (1996) +2 other references |
Slovakia | |
|
Gozaisho Mine, Iwaki City, Fukushima Prefecture, Japan