Petarasite Mineral Data

General Petarasite Information

Chemical Formula:

Na5Zr2Si6O18(Cl,OH)•2(H2O)

Composition:

Molecular Weight = 832.99 gm

Sodium 12.97 % Na 17.49 % Na₂O

Calcium 0.48 % Ca 0.67 % CaO

Zirconium 21.90 % Zr 29.59 % ZrO₂

Silicon 20.23 % Si 43.28 % SiO₂

Hydrogen 0.80 % H 7.14 % H₂O

Chlorine 2.13 % Cl 2.13 % Cl

- % Cl -0.48 % -O=Cl₂

Oxygen 41.49 % O

______ ______

100.00 % 99.81 % = TOTAL OXIDE

Empirical Formula:

Na_4.7Ca_0.1Zr₂Si₆O₁₈(OH)_0.6Cl_0.5•3(H₂O)

Environment:

In a biotite-microcline xenolith and in pegmatitic veins in a nepheline syenite.

IMA Status:

Approved IMA 1980

Locality:

Mont Saint-Hilaire, Quebec, Canada. Link to MinDat.org Location Data.

Name Origin:

Named for Peter Tarasoff, amateur mineralogist, Dollard-des-Ormeaux, Quebec, Canada.

Name Pronunciation:

Petarasite + Pronunciation

Synonym:

ICSD 20150

IMA1979-063

PDF 33-1310

Petarasite Image

Images:

Petarasite

Comments: Mottled tan prismatic petarasite crystal in syenite rock.
Location: De Mix Quarry, Mont Saint Hilaire, Rouville County, Quebec, Canada. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Petarasite Crystallography

Axial Ratios:

a:b:c =0.7448:1:0.4569

Cell Dimensions:

a = 10.7956, b = 14.4928, c = 6.6229, Z = 2; beta = 113.214° V = 952.32 Den(Calc)= 2.90

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/m

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 2.924(1), 4.1(1), 7.25(0.7),

Physical Properties of Petarasite

Cleavage:

{110} Perfect, {010} Good, {001} Distinct

Color:

Brownish yellow, Greenish yellow.

Density:

2.88

Diaphaneity:

Transparent to Translucent

Fracture:

Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

Irregular Grains - Occurs as splotchy, anhedral crystals forming inclusions in other minerals or rocks.

Hardness:

5-5.5 - Apatite-Knife Blade

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Petarasite

Gladstone-Dale:

CI meas= 0.031 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.038 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2099,KPDmeas= 0.2113,KC= 0.2181
Ncalc = 1.63

Optical Data:

Biaxial (+), a=1.595-1.596, b=1.598-1.6, g=1.631-1.632, bire=0.0360, 2V(Calc)=36-40, 2V(Meas)=29-43. Dispersion r < v weak.

Pleochroism (x):

colorless.

Pleochroism (y):

pale greenish yellow.

Pleochroism (z):

pale greenish yellow.

Calculated Properties of Petarasite

Electron Density:

Bulk Density (Electron Density)=2.80 gm/cc
note: Specific Gravity of Petarasite =2.88 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Petarasite= 30.12 barns/electron
U=PE_Petarasite x rElectron Density= 84.49 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Petarasite is Not Radioactive

Petarasite Classification

Dana Class:

61.01.02b.03 (61)Cyclosilicate Six-Membered Rings

(61.01)with [Si6O18] rings; possible (OH) and Al substitution

(61.01.02b)Lovozerite group (Ortho and MON subgroup)

61.01.02b.01 Imandrite Na12Ca3Fe2Si12O36 Pnnm 2/m 2/m 2/m

61.01.02b.02 Koashvite Na6(Ca,Mn)(Ti,Fe)Si6O18•(H2O) Pmnb 2/m 2/m 2/m

61.01.02b.03 Petarasite Na5Zr2Si6O18(Cl,OH)•2(H2O) P 2₁/m 2/m

61.01.02b.04 Litvinskite! Na2([],Na,Mn)Zr[Si6O12(OH,O)6] Cm m

Strunz Class:

09.CJ.40 09 - SILICATES (Germanates)

09.C - Cyclosilicates

09.CJ -[Si6O18]12- 6-membered single rings (sechser-Einfachringe),

09.CJ.40 Petarasite Na5Zr2Si6O18(Cl,OH)•2(H2O) P 2₁/m 2/m

Other Petarasite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic2)

See Also:

Links to other databases for Petarasite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - GeoScienceWorld
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - WWW-MINCRYST

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Print or Cut-and-Paste your Petarasite Specimen Label here :

Petarasite

Na5Zr2Si6O18(Cl,OH)•2(H2O)
Dana No: 61.01.02b.03 Strunz No: 09.CJ.40
Locality:

Notes:

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