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 % Na2 O
Calcium 12.76 % Ca 17.86 % CaO
Magnesium 11.61 % Mg 19.25 % MgO
Phosphorus 14.79 % P 33.90 % P2 O5
Hydrogen 1.77 % H 15.78 % H2 O
Carbon 1.91 % C 7.01 % CO2
Oxygen 53.50 % O
______ ______
100.00 % 98.73 % = TOTAL OXIDE
Empirical Formula:
NaCa2 Mg3 (PO4 )2 (PO3 OH)(CO3 )(OH)2 •4(H2 O)
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 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
X Ray Diffraction:
By Intensity(I/Io ): 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:
PEGirvasite = 2.64 barns/electronU=PEGirvasite x r Electron 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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Girvasite
NaCa2Mg3(PO4)2[PO2(OH)2](CO3)(OH)2•4(H2O)
Dana No: 43.05.17.01 Strunz No: 08.DO.05
Locality:
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