Girvasite Mineral Data

General Girvasite Information

Chemical Formula:

NaCa2Mg3(PO4)2[PO2(OH)2](CO3)(OH)2•4(H2O)

Composition:

Molecular Weight = 628.07 gm

Sodium 3.66 % Na 4.93 % Na₂O

Calcium 12.76 % Ca 17.86 % CaO

Magnesium 11.61 % Mg 19.25 % MgO

Phosphorus 14.79 % P 33.90 % P₂O₅

Hydrogen 1.77 % H 15.78 % H₂O

Carbon 1.91 % C 7.01 % CO₂

Oxygen 53.50 % O

______ ______

100.00 % 98.73 % = TOTAL OXIDE

Empirical Formula:

NaCa₂Mg₃(PO₄)₂(PO₃OH)(CO₃)(OH)₂•4(H₂O)

Environment:

Low-temperature hydrothermal mineral filling solution cavities in dolomite carbonatite in a differentiated alkaline massif.

IMA Status:

Approved IMA 1990

Locality:

Zheleznyi iron mine, Kovdor massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.

Name Origin:

Named for Lake Girvas, northwest of the Kovdor massif, Kola Peninsula, Russia.

Name Pronunciation:

Girvasite + Pronunciation

Synonym:

ICSD 39339

IMA1988-046

PDF 42-1397

Girvasite Image

Images:

Girvasite

Comments: Translucent aggregate of girvasite.
Location: Kovdor Mine, Kola Peninsula, Murmansk District, Russia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Girvasite Crystallography

Axial Ratios:

a:b:c =0.5304:1:1.7447

Cell Dimensions:

a = 6.507, b = 12.267, c = 21.403, Z = 4; beta = 90.37° V = 1,708.38 Den(Calc)= 2.44

Crystal System:

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

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

By Intensity(I/I_o): 10.72(1), 3.57(0.8), 2.016(0.35),

Physical Properties of Girvasite

Cleavage:

{???} Perfect

Color:

Colorless, White.

Density:

2.46

Diaphaneity:

Transparent

Hardness:

3.5 - Copper Penny

Luster:

Vitreous - Silky

Streak:

white

Optical Properties of Girvasite

Gladstone-Dale:

CI meas= -0.044 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.053 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2272,KPDmeas= 0.2253,KC= 0.2158
Ncalc = 1.53

Optical Data:

Biaxial (-), a=1.541, b=1.557, g=1.565, bire=0.0240, 2V(Calc)=68, 2V(Meas)=60-71.

Calculated Properties of Girvasite

Electron Density:

Bulk Density (Electron Density)=2.48 gm/cc
note: Specific Gravity of Girvasite =2.46 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Girvasite= 2.64 barns/electron
U=PE_Girvasite x rElectron Density= 6.55 barns/cc.

Radioactivity:

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

Girvasite Classification

Dana Class:

43.05.17.01 (43)Compound Phosphates, etc.

(43.05)(Hydrated Compound Anions With Hydroxyl or Halogen)

(43.05.17)Dana Group

43.05.17.01 Girvasite NaCa2Mg3(PO4)2[PO2(OH)2](CO3)(OH)2•4(H2O) P 2₁/c 2/m

Strunz Class:

08.DO.05 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DO -With CO3, SO4, SiO4

08.DO.05 Girvasite NaCa2Mg3(PO4)2[PO2(OH)2](CO3)(OH)2•4(H2O) P 2₁/c 2/m

Other Girvasite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Am.Min.,Vol.76,p667,1991) OPTIC PROP.(Am.Min.,Vol.76,p667,1991)

See Also:

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

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

Girvasite

NaCa2Mg3(PO4)2[PO2(OH)2](CO3)(OH)2•4(H2O)
Dana No: 43.05.17.01 Strunz No: 08.DO.05
Locality:

Notes:

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