Parakeldyshite Mineral Data

[Fine Minerals] [What's New] [Mineral Galleries] [My Collection] [Mineral Auctions]
Weinrich Minerals, Inc
Full-time professional mineral dealer with over 31 years experience in mineral collecting
And 15 years selling mineral specimens on the internet and at major mineral shows

General Parakeldyshite Information

Chemical Formula:

Na2ZrSi2O7

Composition:

Molecular Weight = 305.37 gm

Sodium 15.06 % Na 20.30 % Na₂O

Zirconium 29.87 % Zr 40.35 % ZrO₂

Silicon 18.39 % Si 39.35 % SiO₂

Oxygen 36.68 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₂ZrSi₂O₇

Environment:

As masses in nepheline syenite pegmatites which cut a foyaite.

IMA Status:

Approved IMA 1975

Locality:

Mt. Takhtarvumchorr and elsewhere in the Khibiny massif, and on Mt. Alluaiv and elsewhere in the Lovozero massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.

Name Origin:

Named from the Greek para, for near, and its relation to keldyshite.

Name Pronunciation:

Parakeldyshite + Pronunciation

Synonym:

ICSD 24866

PDF 39-209

Parakeldyshite Image

Images:

Parakeldyshite

Comments: White pearly crystalline parakeldyshite in rock.
Location: Lagendalen, Larvik, Vestfold, Norway. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Parakeldyshite Crystallography

Axial Ratios:

a:b:c =0.8201:1:1.3328

Cell Dimensions:

a = 5.419, b = 6.607, c = 8.806, Z = 2; alpha = 71.5°, beta = 87.15°, gamma = 85.63° V = 297.75 Den(Calc)= 3.41

Crystal System:

Triclinic - PinacoidalH-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 3.963(1), 2.913(0.9), 4.179(0.8),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Voronkov A A , Shumyatskaya N G , Pyatenko Y A , Journal of Structural Chemistry , 11 (1970) p.866-867, Crystal structure of a new natural modification of Na2Zr[Si2O7], Locality: synthetic

Physical Properties of Parakeldyshite

Color:

Bluish white, White.

Density:

3.39

Diaphaneity:

Translucent

Hardness:

5.5-6 - Knife Blade-Orthoclase

Luminescence:

Fluorescent, Short UV=orange-white.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Parakeldyshite

Gladstone-Dale:

CI meas= 0.007 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.01 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2034,KPDmeas= 0.204,KC= 0.2056
Ncalc = 1.7

Optical Data:

Biaxial (-), a=1.67, b=1.692, g=1.713, bire=0.0430

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Parakeldyshite

Electron Density:

Bulk Density (Electron Density)=3.24 gm/cc
note: Specific Gravity of Parakeldyshite =3.39 gm/cc.

Fermion Index:

Fermion Index = 0.04
Boson Index = 0.96

Photoelectric:

PE_{Parakeldyshite}= 41.12 barns/electron
U=PE_{Parakeldyshite} x rElectron Density= 133.28 barns/cc.

Radioactivity:

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

Parakeldyshite Classification

Dana Class:

55.02.02.03 (55)Sorosilicate Si2O7 Groups, Generally with No Additional Anions

(55.02)with cations in [6] coordination

(55.02.02)Keldyshite group

55.02.02.01 Keldyshite Na2-xHxZrSi2O7•n(H2O) P1 1

55.02.02.02 Khibinskite K2ZrSi2O7 B2/m 2/m

55.02.02.03 Parakeldyshite Na2ZrSi2O7 P1 1

Strunz Class:

09.BC.10 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BC -Si2O7 groups, without non-tetrahedral anions;

09.BC.10 Khibinskite K2ZrSi2O7 B2/m 2/m

09.BC.10 Keldyshite Na2-xHxZrSi2O7•n(H2O) P1 1

09.BC.10 Parakeldyshite Na2ZrSi2O7 P1 1

Other Parakeldyshite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990;www.saint-hilaire.ca) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Parakeldyshite :
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

Search for Parakeldyshite using:

[ALTAVISTA] [AOL] [bing] [GeoScienceWorld] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Parakeldyshite :

B & L Fine Minerals

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

John Betts Fine Minerals

Lapis Mineral Journal

Mineral News

UV Tools

Wrights Rock Shop

Translate Parakeldyshite Mineral Data :

Ask about Parakeldyshite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Parakeldyshite

Na2ZrSi2O7
Dana No: 55.02.02.03 Strunz No: 09.BC.10
Locality:

Notes: