Manganoneptunite
A valid IMA mineral species - grandfathered
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About Manganoneptunite
Formula:
KNa2Li(Mn2+)2Ti2[Si4O12]2
Colour:
Red
Lustre:
Vitreous
Hardness:
5 - 6
Specific Gravity:
3.17 - 3.20
Crystal System:
Monoclinic
Member of:
Name:
For being the manganese analogue of neptunite. The earlier name was mangan-neptunite, but it was changed to manganoneptunite by the IMA in 2008 (Burke 2008).
Unique Identifiers
Mindat ID:
2564
Long-form identifier:
mindat:1:1:2564:1
IMA Classification of Manganoneptunite
Approved, 'Grandfathered' (first described prior to 1959)
IMA status notes:
Renamed by the IMA
IMA Formula:
KNa2LiMn2+2Ti4+2Si8O24
First published:
1923
Classification of Manganoneptunite
9.EH.05
9 : SILICATES (Germanates)
E : Phyllosilicates
H : Transitional structures between phyllosilicate and other silicate units
9 : SILICATES (Germanates)
E : Phyllosilicates
H : Transitional structures between phyllosilicate and other silicate units
Dana 7th ed.:
70.4.1.2
70.4.1.2
70 : INOSILICATES Column or Tube Structures
4 : Column or Tube Structures with linked chains forming cages
70 : INOSILICATES Column or Tube Structures
4 : Column or Tube Structures with linked chains forming cages
14.9.27
14 : Silicates not Containing Aluminum
9 : Silicates of Ti
14 : Silicates not Containing Aluminum
9 : Silicates of Ti
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 |
|---|---|---|
| Mnnpt | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Manganoneptunite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Manganoneptunite
Vitreous
Transparency:
Translucent
Colour:
Red
Streak:
Brick-red, reddish brown.
Hardness:
5 - 6 on Mohs scale
Tenacity:
Brittle
Cleavage:
Distinct/Good
Distinct in two directions, intersecting at ~80°.
Distinct in two directions, intersecting at ~80°.
Fracture:
Irregular/Uneven, Conchoidal
Density:
3.17 - 3.20 g/cm3 (Measured) 3.26 g/cm3 (Calculated)
Optical Data of Manganoneptunite
Type:
Biaxial (+)
RI values:
nα = 1.691 - 1.697 nβ = 1.693 - 1.700 nγ = 1.713 - 1.728
2V:
Measured: 31° to 36°, Calculated: 40°
Max. Birefringence:
δ = 0.022 - 0.031
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:
r > v strong
Optical Extinction:
Y = b; Z ∧ c = 16°-20°.
Pleochroism:
Strong
Comments:
X = light yellow; Y = orange or yellow-orange; Z = red-orange.
Comments:
Absorption: Z > Y > X.
Chemistry of Manganoneptunite
Mindat Formula:
KNa2Li(Mn2+)2Ti2[Si4O12]2
Element Weights:
Crystallography of Manganoneptunite
Crystal System:
Monoclinic
Class (H-M):
m - Domatic
Space Group:
Bb
Setting:
Cc
Cell Parameters:
a = 16.4821(6) Å, b = 12.5195(4) Å, c = 10.0292(3) Å
β = 115.474(1)°
β = 115.474(1)°
Ratio:
a:b:c = 1.317 : 1 : 0.801
Unit Cell V:
1868.31 ų
Morphology:
Prismatic crystals, elongated along [001]. Forms include {110}, {001}, {100}. Also {111}, {111} and rare {210}.
Twinning:
Contact twinning on {001}.
Crystal Structure
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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) |
|---|---|---|---|---|---|---|---|
| 0015717 | Manganoneptunite | Zolotarev A A, Krivovichev S V, Yakovenchuk V N (2007) Refinement of the mangan-neptunite structure Zapiski Vserossijskogo Mineralogicheskogo Obshchestva 136 118-123 | 2007 | Mt. Kaskasnyuncharr, the Khibiny alkaline pluton, Russia | 0 | 293 | |
| 0018809 | Manganoneptunite | Borisov S V, Klevtsova R F, Bakakin V V, Belov N V (1966) The crystal structure of neptunite Soviet Physics Crystallography 10 684-689 | 1966 | Lovozero, Russia | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 2.485 Å | (100) |
| 1.506 Å | (100) |
| 1.483 Å | (90) |
| 2.170 Å | (80) |
| 1.924 Å | (70) |
| 2.841 Å | (60) |
| 2.948 Å | (50) |
Comments:
Lovozero massif, Russia.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 35 : Ultra-alkali and agpaitic igneous rocks |
Type Occurrence of Manganoneptunite
General Appearance of Type Material:
Dark cherry-red crystalline granular aggregates, some of significant size and included with aegirine.
Place of Conservation of Type Material:
No designated type material.
Geological Setting of Type Material:
Pegmatite in nepheline syenite.
Associated Minerals at Type Locality:
Synonyms of Manganoneptunite
Other Language Names for Manganoneptunite
Relationship of Manganoneptunite to other Species
Member of:
Other Members of Neptunite Group:
| Magnesioneptunite | KNa2Li(Mg)2Ti2[Si4O12]2 | Mon. 2/m : B2/b |
| Neptunite | KNa2Li(Fe2+)2Ti2[Si4O12]2 | Mon. m : Bb |
| Rotherkopfite | KNa2Fe2+(Fe2+)2(Ti1.5Fe2+0.5)[Si4O12]2 | Mon. 2/m : B2/b |
| Watatsumiite | KNa2Li(Mn2+)2V4+2[Si4O12]2 | Mon. m : Bb |
Forms a series with:
Common Associates
Associations Based on Photo Data:
| 69 photos of Manganoneptunite associated with Aegirine | NaFe3+Si2O6 |
| 69 photos of Manganoneptunite associated with Serandite | NaMn2+2Si3O8(OH) |
| 36 photos of Manganoneptunite associated with Albite | Na(AlSi3O8) |
| 34 photos of Manganoneptunite associated with Catapleiite | Na2Zr(Si3O9) · 2H2O |
| 25 photos of Manganoneptunite associated with Shkatulkalite | Na2Nb2Na3Ti(Si2O7)2O2(FO)(H2O)4(H2O)3 |
| 23 photos of Manganoneptunite associated with Microcline | K(AlSi3O8) |
| 22 photos of Manganoneptunite associated with Natrolite | Na2Al2Si3O10 · 2H2O |
| 21 photos of Manganoneptunite associated with Analcime | Na(AlSi2O6) · H2O |
| 19 photos of Manganoneptunite associated with Ussingite | Na2AlSi3O8OH |
| 18 photos of Manganoneptunite associated with Polylithionite | KLi2Al(Si4O10)(F,OH)2 |
Related Minerals - Strunz-mindat Grouping
| 9.EH.05 | Magnesioneptunite | KNa2Li(Mg)2Ti2[Si4O12]2 |
| 9.EH.05 | Neptunite | KNa2Li(Fe2+)2Ti2[Si4O12]2 |
| 9.EH.05 | Watatsumiite | KNa2Li(Mn2+)2V4+2[Si4O12]2 |
| 9.EH.05 | Rotherkopfite | KNa2Fe2+(Fe2+)2(Ti1.5Fe2+0.5)[Si4O12]2 |
| 9.EH.10 | Grumantite | Na(HSi2O5) · H2O |
| 9.EH.15 | Sarcolite | Na4Ca12Al8Si12O46(SiO4,PO4)(OH,H2O)4(CO3,Cl) |
| 9.EH.20 | Ussingite | Na2AlSi3O8OH |
| 9.EH.25 | Telyushenkoite | (Cs,Na,K)Na6[Be2Al3Si15O39]F2 |
| 9.EH.25 | Leifite | (Na,H2O)Na6[Be2Al2(Al,Si)Si15O39]F2 |
| 9.EH.25 | Eirikite | KNa6Be2(Si15Al3)O39F2 |
| 9.EH.30 | Nafertisite | Na3Fe2+10Ti2(Si6O17)2O2(OH)6F(H2O)2 |
| 9.EH.35 | Veblenite | KNa(Fe2+5Fe3+4Mn7)Nb4(Si2O7)2(Si8O22)2O6(OH)10(H2O)3 |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 0.0000% | 0 | α, β, γ |
| Thorium (Th) | 0.0000% | 0 | α, β, γ |
| Potassium (K) | 4.3141% | 1,337 | β, γ |
For comparison:
- Banana: ~15 Bq per fruit
- Granite: 1,000–3,000 Bq/kg
- EU exemption limit: 10,000 Bq/kg
Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.
Interactive Simulator:
Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!
Activity: –
| Distance | Dose rate | Risk |
|---|---|---|
| 1 cm | ||
| 10 cm | ||
| 1 m |
The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).
D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield
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 Manganoneptunite
mindat.org URL:
https://www.mindat.org/min-2564.html
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References for Manganoneptunite
Localities for Manganoneptunite
Showing 41 localities.
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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.
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Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada