Poudretteite
A valid IMA mineral species
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About Poudretteite
Formula:
K◻2Na2B3[Si12O30]
Colour:
Colourless, very pale pink
Lustre:
Vitreous
Hardness:
5
Specific Gravity:
2.51
Crystal System:
Hexagonal
Member of:
Name:
The mineral was named in honor of the Poudrette family, owners and operators of the original R. Poudrette quarry, established in 1959, and from 1992 to 2007, the enlarged Poudrette quarry, which incorporates the former Demix and all other previously operated quarries into a single entity. The Poudrette quarry is one the world's great mineralogical treasures, and the type locality for 73 mineral species. The Poudrette family has contributed greatly to the mineralogical studies of Mont Saint-Hilaire by generously allowing access to their quarry.
Visit gemdat.org for Unique Identifiers
Mindat ID:
3272
Long-form identifier:
mindat:1:1:3272:4
IMA Classification of Poudretteite
Approved
IMA Formula:
KNa2(B3Si12)O30
Approval year:
1986
First published:
1987
Classification of Poudretteite
9.CM.05
9 : SILICATES (Germanates)
C : Cyclosilicates
M : [Si6O18]12- 6-membered double rings (sechser-Doppelringe)
9 : SILICATES (Germanates)
C : Cyclosilicates
M : [Si6O18]12- 6-membered double rings (sechser-Doppelringe)
63.2.1a.8
63 : CYCLOSILICATES Condensed Rings
2 : Condensed Rings (Milarite - Osumilite group)
63 : CYCLOSILICATES Condensed Rings
2 : Condensed Rings (Milarite - Osumilite group)
17.5.8
17 : Silicates Containing other Anions
5 : Borosilicates
17 : Silicates Containing other Anions
5 : Borosilicates
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Pou | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Pou | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Poudretteite
Vitreous
Transparency:
Transparent
Colour:
Colourless, very pale pink
Streak:
White
Hardness:
5 on Mohs scale
Tenacity:
Brittle
Cleavage:
None Observed
Fracture:
Splintery
Density:
2.51(1) g/cm3 (Measured) 2.53 g/cm3 (Calculated)
Optical Data of Poudretteite
Type:
Uniaxial (+)
RI values:
nω = 1.516(1) nε = 1.532(1)
Max. Birefringence:
δ = 0.016
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:
Low (negative)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Chemistry of Poudretteite
Mindat Formula:
K◻2Na2B3[Si12O30]
Element Weights:
Crystallography of Poudretteite
Crystal System:
Hexagonal
Class (H-M):
6/mmm(6/m2/m2/m) - Dihexagonal Dipyramidal
Space Group:
P6/mcc
Setting:
P6/mcc
Cell Parameters:
a = 10.239(1) Å, c = 13.485(3) Å
Ratio:
a:c = 1 : 1.317
Unit Cell V:
1,224.32 ų (Calculated from Unit Cell)
Z:
2
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) |
|---|---|---|---|---|---|---|---|
| 0005217 | Poudretteite | Grice J D, Ercit T S, Van Velthuizen J, Dunn P J (1987) Poudretteite, KNa2B3Si12O30, a new member of the osumilite group from Mont Saint-Hilaire, Quebec, and its crystal structure The Canadian Mineralogist 25 763-766 |  | 1987 | Mont Saint-Hilaire, Quebec, Canada | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.13 Å | (100) |
| 3.253 Å | (100) |
| 2.815 Å | (60) |
| 2.686 Å | (50) |
| 2.956 Å | (40) |
| 1.818 Å | (40) |
| 6.74 Å | (30) |
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 Poudretteite
General Appearance of Type Material:
Clear, colorless to very pale pink, equidimensional, subhedral prisms up to 5 mm.
Place of Conservation of Type Material:
Canadian Museum of Nature, Ottawa, Canada, 51743 and 51791.
National Museum of Natural History, Washington, D.C., USA, 163776.
National Museum of Natural History, Washington, D.C., USA, 163776.
Geological Setting of Type Material:
In a marble xenolith included in nepheline syenite.
Associated Minerals at Type Locality:
Synonyms of Poudretteite
Other Language Names for Poudretteite
Relationship of Poudretteite to other Species
Member of:
Other Members of Osumilite Group:
| Agakhanovite-(Y) | K◻2(YCa)Be3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Almarudite | K◻2Mn2+2(Be2Al)[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mmm |
| Aluminosugilite | KNa2Al2Li3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Armenite | Ba(H2O)2Ca2Al3[Al3Si9O30] | Orth. mmm(2/m2/m2/m) : Pnna |
| Berezanskite | K◻2Ti2Li3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Brannockite | K◻2Sn2Li3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Chayesite | K◻2Mg2(Mg2Fe3+)[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Darapiosite | KNa2Mn2(Zn2Li)[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Dusmatovite | K(K◻)Mn2+2Zn3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Eifelite | KNa2(MgNa)Mg3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Friedrichbeckeite | K(◻Na)Mg2(Be2Mg)[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Klöchite | K◻2(Fe2+Fe3+)Zn3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P63/mmc |
| Laurentthomasite | K◻2Mg2(Be2Al)[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Merrihueite | K(◻Na)Fe2+2Fe2+3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Milarite | K(◻H2O)Ca2(Be2Al)[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Oftedalite | K◻2(ScCa)Be3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Osumilite | K◻2Fe2+2Al3[Al2Si10O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Osumilite-(Mg) | K◻2Mg2Al3[Al2Si10O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Plechovite | Ca2[K(H2O)]KBe3Si12O30 | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Roedderite | K(◻Na)Mg2Mg3[Si12O30] | Hex. 6m2 : P62c |
| Shibkovite | K(◻K)Ca2Zn3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Sogdianite | K◻2Zr2Li3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Sugilite | KNa2Fe3+2Li3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| Trattnerite | ◻(◻)2Fe3+2Mg3[Si12O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
| 'UM1990-73-SiO:KMnNaZn' | K(KNa0.5◻0.5)(Mn1.5Na0.5)Zn3[Si12O30] | Hex. |
| 'Unnamed (Mn3+-dominant analog of Sugilite)' | KNa2Mn3+2Li3[Si12O30] | |
| Yagiite | Na◻2Mg2Al3[Al2Si10O30] | Hex. 6/mmm(6/m2/m2/m) : P6/mcc |
Common Associates
Associations Based on Photo Data:
| 1 photo of Poudretteite associated with Serandite | NaMn2+2Si3O8(OH) |
| 1 photo of Poudretteite associated with Manganoneptunite | KNa2Li(Mn2+)2Ti2[Si4O12]2 |
| 1 photo of Poudretteite associated with Analcime | Na(AlSi2O6) · H2O |
| 1 photo of Poudretteite associated with Quartz | SiO2 |
| 1 photo of Poudretteite associated with Phlogopite | KMg3(AlSi3O10)(OH)2 |
| 1 photo of Poudretteite associated with Johachidolite | CaAlB3O7 |
Related Minerals - Strunz-mindat Grouping
| 9.CM. | Agakhanovite-(Y) | K◻2(YCa)Be3[Si12O30] |
| 9.CM. | Plechovite | Ca2[K(H2O)]KBe3Si12O30 |
| 9.CM.05 | Friedrichbeckeite | K(◻Na)Mg2(Be2Mg)[Si12O30] |
| 9.CM.05 | Laurentthomasite | K◻2Mg2(Be2Al)[Si12O30] |
| 9.CM.05 | 'UM1990-73-SiO:KMnNaZn' | K(KNa0.5◻0.5)(Mn1.5Na0.5)Zn3[Si12O30] |
| 9.CM.05 | Eifelite | KNa2(MgNa)Mg3[Si12O30] |
| 9.CM.05 | Almarudite | K◻2Mn2+2(Be2Al)[Si12O30] |
| 9.CM.05 | Armenite | Ba(H2O)2Ca2Al3[Al3Si9O30] |
| 9.CM.05 | Merrihueite | K(◻Na)Fe2+2Fe2+3[Si12O30] |
| 9.CM.05 | Oftedalite | K◻2(ScCa)Be3[Si12O30] |
| 9.CM.05 | Roedderite | K(◻Na)Mg2Mg3[Si12O30] |
| 9.CM.05 | Shibkovite | K(◻K)Ca2Zn3[Si12O30] |
| 9.CM.05 | Sogdianite | K◻2Zr2Li3[Si12O30] |
| 9.CM.05 | Milarite | K(◻H2O)Ca2(Be2Al)[Si12O30] |
| 9.CM.05 | Berezanskite | K◻2Ti2Li3[Si12O30] |
| 9.CM.05 | Darapiosite | KNa2Mn2(Zn2Li)[Si12O30] |
| 9.CM.05 | Chayesite | K◻2Mg2(Mg2Fe3+)[Si12O30] |
| 9.CM.05 | Osumilite-(Mg) | K◻2Mg2Al3[Al2Si10O30] |
| 9.CM.05 | Osumilite | K◻2Fe2+2Al3[Al2Si10O30] |
| 9.CM.05 | Sugilite | KNa2Fe3+2Li3[Si12O30] |
| 9.CM.05 | Trattnerite | ◻(◻)2Fe3+2Mg3[Si12O30] |
| 9.CM.05 | Brannockite | K◻2Sn2Li3[Si12O30] |
| 9.CM.05 | Klöchite | K◻2(Fe2+Fe3+)Zn3[Si12O30] |
| 9.CM.05 | Dusmatovite | K(K◻)Mn2+2Zn3[Si12O30] |
| 9.CM.05 | Yagiite | Na◻2Mg2Al3[Al2Si10O30] |
| 9.CM.9.CM. | Aluminosugilite | KNa2Al2Li3[Si12O30] |
| 9.CM.10 | Faizievite | K2Na(Ca6Na)Ti4Li6[Si6O18]2[Si12O30]F2 |
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) | 4.1838% | 1,297 | 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 Poudretteite
mindat.org URL:
https://www.mindat.org/min-3272.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Poudretteite
Localities for Poudretteite
Showing 5 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.
Canada (TL) | |
| Grice et al. (1987) +1 other reference |
Myanmar | |
| Smith et al. (2003) +1 other reference |
| Themelis (2008) |
| Themelis (2008) +1 other reference |
| California Institute of Technology ... +1 other reference |
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Pyant Gyi mine, Pein-Pyit, Mogok Township, Pyin-Oo-Lwin District, Mandalay Region, Myanmar