Farringtonite Mineral Data
General Farringtonite Information
Chemical Formula:
Mg3(PO4)2
Composition:
Molecular Weight = 262.86 gm
Magnesium 27.74 % Mg 46.00 % MgO
Phosphorus 23.57 % P 54.00 % P2 O5
Oxygen 48.69 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Mg3 (PO4 )2
Environment:
Component in pallasite meteorites, rimming and cementing olivine nodules.
IMA Status:
Approved IMA 1961
Locality:
Springwater, Krasnojarsk, Zaisho, Imilac, and Port Orford pallasite meteorites. Link to MinDat.org Location Data.
Name Origin:
Named for Oliver Cummings Farrington (1864-1933), Curator of Geology, Field Museum of Natural History, Chicago, Illinois, USA.
Name Pronunciation:
Farringtonite + Pronunciation
Synonym:
ICSD 31005
PDF 33-876
Farringtonite Image
Images:
Farringtonite
Comments: B&W BSE image of a fragment of farringtonite mounted in an epoxy grain mount.
Location: Springwater Pallasite, Saskatchewan, Canada (1931).
Scale: See Image.
© Diederik Visser
Farringtonite Crystallography
Axial Ratios:
a:b:c =0.9234:1:0.6172
Cell Dimensions:
a = 7.6, b = 8.23, c = 5.08, Z = 2; beta = 94.06° V = 316.95 Den(Calc)= 2.75
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21 /a
X Ray Diffraction:
By Intensity(I/Io ): 3.44(1), 3.85(0.9), 4.08(0.5),
Physical Properties of Farringtonite
Cleavage:
{100} Good, {010} Good
Color:
White, Wax yellow.
Density:
2.74
Streak:
white
Optical Properties of Farringtonite
Gladstone-Dale:
CI meas = -0.047 (Good) - where the CI = (1-KPDmeas /KC ) CI calc = -0.044 (Good) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.1992,KPDmeas = 0.1999,KC = 0.1908 Ncalc = 1.52
Optical Data:
Biaxial (+), a=1.54, b=1.544, g=1.559, bire=0.0190, 2V(Calc)=56, 2V(Meas)=54-55.
Calculated Properties of Farringtonite
Electron Density:
Bulk Density (Electron Density)=2.72 gm/cc note: Specific Gravity of Farringtonite =2.75 gm/cc.
Fermion Index:
Fermion Index = 0.02 Boson Index = 0.98
Photoelectric:
PEFarringtonite = 1.74 barns/electronU=PEFarringtonite x r Electron Density= 4.73 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Farringtonite is Not Radioactive
Farringtonite Classification
Dana Class:
38.03.01.02 (38) Anhydrous Phosphates, etc
(38.03) (A+ B++)3 (XO4)2
(38.03.01) Sarcopside Group
38.03.01.01 Sarcopside (Fe,Mn,Mg)3(PO4)2 P 21 /a 2/m
38.03.01.02 Farringtonite Mg3(PO4)2 P 21 /a 2/m
38.03.01.03 Chopinite ! (Mg,Fe)3(PO4)2 P 21 /c 2/m
Strunz Class:
08.AB.05 08 - PHOSPHATES, ARSENATES, VANADATES
08.A - Phosphates, etc. without additional anions, without H2O
08.AB -With medium-sized cations
08.AB.05 Farringtonite Mg3(PO4)2 P 21 /a 2/m
Other Farringtonite Information
References:
NAME( AntBidBlaNic5) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
See Also:
Links to other databases for Farringtonite :
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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Farringtonite
Mg3(PO4)2
Dana No: 38.03.01.02 Strunz No: 08.AB.05
Locality:
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