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 % P₂O₅

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

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

By Intensity(I/I_o): 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:

PE_{Farringtonite}= 1.74 barns/electron
U=PE_{Farringtonite} x rElectron 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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Print or Cut-and-Paste your Farringtonite Specimen Label here :

Farringtonite

Mg3(PO4)2
Dana No: 38.03.01.02 Strunz No: 08.AB.05
Locality:

Notes:

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