Stanfieldite Mineral Data

General Stanfieldite Information

Chemical Formula:

Ca4(Mg,Fe++,Mn)5(PO4)6

Composition:

Molecular Weight = 906.55 gm

Calcium 17.68 % Ca 24.74 % CaO

Magnesium 7.78 % Mg 12.89 % MgO

Manganese 1.21 % Mn 1.56 % MnO

Iron 10.47 % Fe 13.47 % FeO

Phosphorus 20.50 % P 46.97 % P₂O₅

Oxygen 42.36 % O

______ ______

100.00 % 99.65 % = TOTAL OXIDE

Empirical Formula:

Ca₄Mg_2.9Fe²⁺_1.7Mn²⁺_0.2(PO₄)₆

Environment:

A rare component of some meteorites.

IMA Status:

Approved IMA 1967

Locality:

Esterville mesosiderite meteorite. Link to MinDat.org Location Data.

Name Origin:

Named for Stanley Field (1875-1964), former Chairman of the Board of Turstees of the Field Museum of Natural History, Chicago, Illinois, USA.

Name Pronunciation:

Stanfieldite + Pronunciation

Synonym:

ICSD 23642

PDF 20-223

Stanfieldite Image

Images:

Stanfieldite

Comments: B&W BSE image of a fragment of stanfieldite in an epoxy grain mount.
Location: Brahin Meteorite, Pallasite, Minsk, Belarus (1810). Scale: See Image.
© Diederik Visser

Stanfieldite Crystallography

Axial Ratios:

a:b:c =1.7263:1:2.2912

Cell Dimensions:

a = 17.267, b = 10.002, c = 22.917, Z = 8; beta = 100.517° V = 3,891.38 Den(Calc)= 3.09

Crystal System:

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

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

By Intensity(I/I_o): 2.817(1), 2.505(0.8), 3.747(0.8),

Physical Properties of Stanfieldite

Color:

Yellow brown, Reddish yellow.

Density:

3.15

Diaphaneity:

Transparent

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Hardness:

4-5 - Fluorite-Apatite

Luster:

Vitreous (Glassy)

Optical Properties of Stanfieldite

Gladstone-Dale:

CI meas= -0.01 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.029 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1977,KPDmeas= 0.194,KC= 0.1921
Ncalc = 1.59 - 1.61

Optical Data:

Biaxial (+), a=1.594-1.619, b=1.596-1.622, g=1.604-1.631, bire=0.0100-0.0120, 2V(Calc)=54-62, 2V(Meas)=50-60.

Calculated Properties of Stanfieldite

Electron Density:

Bulk Density (Electron Density)=3.10 gm/cc
note: Specific Gravity of Stanfieldite =3.15 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Stanfieldite= 6.75 barns/electron
U=PE_Stanfieldite x rElectron Density= 20.92 barns/cc.

Radioactivity:

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

Stanfieldite Classification

Dana Class:

38.03.05.01 (38)Anhydrous Phosphates, etc

(38.03)(A+ B++)3 (XO4)2

(38.03.05)Dana Group

38.03.05.01 Stanfieldite Ca4(Mg,Fe,Mn)5(PO4)6 P 2/c 2/m

Strunz Class:

08.AC.70 08 - PHOSPHATES, ARSENATES, VANADATES

08.A - Phosphates, etc. without additional anions, without H2O

08.AC -With medium-sized and large cations

08.AC.70 Stanfieldite Ca4(Mg,Fe,Mn)5(PO4)6 P 2/c 2/m

Other Stanfieldite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic4)

See Also:

Links to other databases for Stanfieldite :
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 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info

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

Stanfieldite

Ca4(Mg,Fe++,Mn)5(PO4)6
Dana No: 38.03.05.01 Strunz No: 08.AC.70
Locality:

Notes:

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