Petarasite
A valid IMA mineral species
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About Petarasite
Peter Tarassoff
Formula:
Na5Zr2(Si6O18)(Cl,OH) · 2H2O
Colour:
Orange to brown, pink, yellow, white
Lustre:
Vitreous
Hardness:
5 - 5½
Specific Gravity:
2.88
Crystal System:
Monoclinic
Name:
Named in 1980 by George Y. Chao, T. T. Chen, and J. Baker in honor of Dr. Peter Tarassoff [b. April 11, 1934 Canada] of Beaconsfield, Quebec, considered to be “the dean” of Mont Saint-Hilaire mineral collectors, for his long (55+ years) and sustained contributions to Mont Saint-Hilaire mineralogy.
Unique Identifiers
Mindat ID:
3172
Long-form identifier:
mindat:1:1:3172:7
Similar Names
| Petersita-(Ce) | A synonym of Petersite-(Ce) | |
| Petersita-(La) | A synonym of Petersite-(La) | |
| Petersite | A synonym | |
| Petersite-(Y) | A valid IMA mineral species | YCu6(PO4)3(OH)6 · 3H2O |
| Pietersite | A variety of 'Chalcedony' [Quartz] | SiO2 |
IMA Classification of Petarasite
Classification of Petarasite
9.CJ.40
9 : SILICATES (Germanates)
C : Cyclosilicates
J : [Si6O18]12- 6-membered single rings (sechser-Einfachringe), without insular complex anions
9 : SILICATES (Germanates)
C : Cyclosilicates
J : [Si6O18]12- 6-membered single rings (sechser-Einfachringe), without insular complex anions
61.1.2b.3
61 : CYCLOSILICATES Six-Membered Rings
1 : Six-Membered Rings with [Si6O18] rings; possible (OH) and Al substitution
61 : CYCLOSILICATES Six-Membered Rings
1 : Six-Membered Rings with [Si6O18] rings; possible (OH) and Al substitution
14.10.11
14 : Silicates not Containing Aluminum
10 : Silicates of Zr or Hf
14 : Silicates not Containing Aluminum
10 : Silicates of Zr or Hf
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 |
|---|---|---|
| Pra | 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 Petarasite
Vitreous
Transparency:
Translucent
Colour:
Orange to brown, pink, yellow, white
Streak:
White.
Hardness:
5 - 5½ on Mohs scale
Cleavage:
Very Good
Very good on {110}, plus 2 more directions distinct.
Very good on {110}, plus 2 more directions distinct.
Fracture:
Sub-Conchoidal
Density:
2.88(1) g/cm3 (Measured) 2.915 g/cm3 (Calculated)
Comment:
Calculated value based on the empirical formula.
Optical Data of Petarasite
Type:
Biaxial (+)
RI values:
nα = 1.595 - 1.596 nβ = 1.598 - 1.6 nγ = 1.631 - 1.632
2V:
Measured: 29° to 43°, Calculated: 36° to 40°
Max. Birefringence:
δ = 0.036
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:
High (positive)
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 biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
r < v, weak.
Optical Extinction:
X = b; Z ∧ c = 41.5°.
Pleochroism:
Weak
Comments:
X = colorless; Y = Z = pale greenish yellow.
Comments:
Absorption: Y = Z > X.
Chemistry of Petarasite
Mindat Formula:
Na5Zr2(Si6O18)(Cl,OH) · 2H2O
Element Weights:
Common Impurities:
Ti,Ca,K
Crystallography of Petarasite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/m
Setting:
P21/m
Cell Parameters:
a = 10.79 Å, b = 14.49 Å, c = 6.62 Å
β = 113.21°
β = 113.21°
Ratio:
a:b:c = 0.745 : 1 : 0.457
Unit Cell V:
951.25 ų (Calculated from Unit Cell)
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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CIF File Best | x | y | z | a | b | c
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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) |
|---|---|---|---|---|---|---|---|
| 0005181 | Petarasite | Ghose S, Wan C, Chao G Y (1980) Petarasite, Na5Zr2Si6O18(Cl,OH).2H2O, a zeolite-type zirconosilicate The Canadian Mineralogist 18 503-509 |  | 1980 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.10 Å | (100) |
| 2.924 Å | (100) |
| 7.25 Å | (70) |
| 6.09 Å | (40) |
| 3.220 Å | (30) |
| 3.041 Å | (30) |
| 1.729 Å | (20) |
Comments:
Poudrette quarry, Mont Saint-Hilaire, Québec, Canada. The data are from Chao et al. (1980).
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 Petarasite
General Appearance of Type Material:
Irregular grains up to 10 mm across.
Place of Conservation of Type Material:
Canadian Museum of Nature, Ottawa, Ontario, Canada, numbers 43721, 43630, 43631 (cotype).
Royal Ontario Museum, Toronto, Ontario, Canada, numbers M36456, M36457, M36458.
Geological Survey of Canada, Ottawa, Ontario, Canada, number 61531 (cotype).
Royal Ontario Museum, Toronto, Ontario, Canada, numbers M36456, M36457, M36458.
Geological Survey of Canada, Ottawa, Ontario, Canada, number 61531 (cotype).
Geological Setting of Type Material:
In a xenolith, composed mainly of coarse grained biotite and microcline, in nepheline syenite.
Associated Minerals at Type Locality:
Synonyms of Petarasite
Other Language Names for Petarasite
Relationship of Petarasite to other Species
Chemically related to group(s):
| Lovozerite Group | A3D3G2M(HxSi6O18) · nH2O (x = 0-6) |
Common Associates
Associations Based on Photo Data:
| 36 photos of Petarasite associated with Catapleiite | Na2Zr(Si3O9) · 2H2O |
| 13 photos of Petarasite associated with Albite | Na(AlSi3O8) |
| 10 photos of Petarasite associated with Aegirine | NaFe3+Si2O6 |
| 5 photos of Petarasite associated with Manganoneptunite | KNa2Li(Mn2+)2Ti2[Si4O12]2 |
| 4 photos of Petarasite associated with Gaidonnayite | Na2Zr(Si3O9) · 2H2O |
| 4 photos of Petarasite associated with Polylithionite | KLi2Al(Si4O10)(F,OH)2 |
| 3 photos of Petarasite associated with Kentbrooksite | (Na,REE)15(Ca,REE)6(Mn2+,Fe2+)3Zr3Nb[Si25O74]F2 · 2H2O |
| 3 photos of Petarasite associated with Genthelvite | Be3Zn4(SiO4)3S |
| 2 photos of Petarasite associated with Analcime | Na(AlSi2O6) · H2O |
| 2 photos of Petarasite associated with Serandite | NaMn2+2Si3O8(OH) |
Related Minerals - Strunz-mindat Grouping
| 9.CJ. | Zolotarevite | Na5Zr[Si6O15(OH)3] · 3H2O |
| 9.CJ. | 'Avdeevite' | NaAl4(Be5Li)(Si6O18)2(H2O)1-2 |
| 9.CJ. | 'Beryllocordierite-Na' | NaMg4(Al5Be)(AlSi5O18)2 · 2H2O |
| 9.CJ. | Sachanbińskiite | NaMn4(Al5Be)(AlSi5O18)2 · 2H2O |
| 9.CJ. | Nakkaalaaqite | K2[Na3Ca]LiCa2Ti2Be4Si12O38 |
| 9.CJ.05 | Johnkoivulaite-(Cs) | Cs[Be2B]Mg2Si6O18 |
| 9.CJ.05 | Beryl | Be3Al2(Si6O18) |
| 9.CJ.05 | Bazzite | Be3Sc2(Si6O18) |
| 9.CJ.05 | Ferroindialite | (Fe2+,Mg)2Al4Si5O18 |
| 9.CJ.05 va | 'Vorobyevite' | Be3Al2(Si6O18) |
| 9.CJ.05 | Stoppaniite | Be3Fe3+2(Si6O18) · H2O |
| 9.CJ.05 | Indialite | Mg2Al3(AlSi5O18) |
| 9.CJ.10 | Sekaninaite | Fe2+2Al4Si5O18 |
| 9.CJ.10 | Cordierite | Mg2Al4Si5O18 |
| 9.CJ.15a | Zirsinalite | Na6(Ca,Mn2+,Fe2+)Zr(Si6O18) |
| 9.CJ.15a | Kapustinite | Na6ZrSi6O16(OH)2 |
| 9.CJ.15a | Townendite | Na8ZrSi6O18 |
| 9.CJ.15a | Combeite | Na4.5Ca3.5Si6O17.5(OH)0.5 |
| 9.CJ.15a | Kazakovite | Na6Mn2+Ti(Si6O18) |
| 9.CJ.15a | Tisinalite | Na3H3(Mn,Ca,Fe)TiSi6(O,OH)18 · 2H2O |
| 9.CJ.15a | Lovozerite | Na2Ca(Zr,Ti)(Si6O12)[(OH)4O2] · H2O |
| 9.CJ.15a | Litvinskite | Na2(◻,Na,Mn)ZrSi6O12(OH,O)6 |
| 9.CJ.15c | Koashvite | Na6(Ca,Mn)(Ti,Fe)Si6O18 · H2O |
| 9.CJ.15b | Imandrite | Na12Ca3Fe3+2(Si6O18)2 |
| 9.CJ.25 | Baratovite | KCa7(Ti,Zr)2Li3Si12O36F2 |
| 9.CJ.25 | Aleksandrovite | KCa7Sn2Li3Si12O36F2 |
| 9.CJ.25 | Katayamalite | KLi3Ca7Ti2(SiO3)12(OH)2 |
| 9.CJ.30 | Dioptase | CuSiO3 · H2O |
| 9.CJ.35 | Kostylevite | K2Zr(Si3O9) · H2O |
| 9.CJ.45 | Gerenite-(Y) | (Ca,Na)2(Y,REE)3Si6O18 · 2H2O |
| 9.CJ.50 | Odintsovite | K2Na4Ca3Ti2Be4Si12O38 |
| 9.CJ.55 | Mathewrogersite | Pb7FeAl3GeSi12O36(OH,H2O)6 |
| 9.CJ.60 | Pezzottaite-(Cs) | Cs(Be2Li)Al2(Si6O18) |
Fluorescence of Petarasite
Not fluorescent.
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 Petarasite
mindat.org URL:
https://www.mindat.org/min-3172.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Petarasite
Reference List:
Chao, George Y., Chen, T. T., Baker, J. (1980) Petarasite, a new hydrated sodium zirconium hydroxychlorosilicate mineral from Mont St-Hilaire, Quebec. The Canadian Mineralogist, 18 (4) 497-502
Fleischer, Michael, Cabri, Louis J. (1981) New Mineral Names. American Mineralogist, 66 (11-12) 1274-1280
Perrault, G., Chao, G. Y., Chen, T. T. (1981) Additional data on petarasite from Mont St. Hilaire, Quebec. The Canadian Mineralogist, 19 (3) 411-413
Localities for Petarasite
Showing 7 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) | |
| Chao et al. (1980) +2 other references |
Norway | |
| Larsen et al. (2010) +1 other reference |
Portugal | |
| Chiappino et al. (2015) |
Russia | |
| Pavel M. Kartashov (n.d.) |
| ... | |
| Хомяков А.П. et al. (1981) | |
USA | |
| Dr. W. Stoll (private communication 2001 & 2004) |
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Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada