Brianite Mineral Data

General Brianite Information

Chemical Formula:

Na2CaMg(PO4)2

Composition:

Molecular Weight = 300.31 gm

Sodium 15.31 % Na 20.64 % Na₂O

Calcium 13.35 % Ca 18.67 % CaO

Magnesium 8.09 % Mg 13.42 % MgO

Phosphorus 20.63 % P 47.27 % P₂O₅

Oxygen 42.62 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₂CaMg(PO₄)₂

Environment:

A very rare component in phosphate modules in an iron meteorite.

IMA Status:

Approved IMA 1967

Locality:

In the Dayton finest (very fine-grained) octahedrite meteorite. Link to MinDat.org Location Data.

Name Origin:

In honor of Dr. Brian Harold Mason (1917- ), U.S. National Museum, Washington, D.C., USA, for his contributions to the study of meteorites.

Name Pronunciation:

Brianite

Synonym:

ICSD 408373

PDF 29-1192

Brianite Crystallography

Axial Ratios:

a:b:c =2.5544:1:1.7456

Cell Dimensions:

a = 13.36, b = 5.23, c = 9.13, Z = 4; beta = 91.2° V = 637.80 Den(Calc)= 3.13

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): 2.625(1), 2.679(0.9), 3.734(0.9),

Physical Properties of Brianite

Color:

Colorless.

Density:

Diaphaneity:

Transparent

Hardness:

4-5 - Fluorite-Apatite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Brianite

Gladstone-Dale:

CI meas= -0.049 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.006 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1929,KPDmeas= 0.2012,KC= 0.1918
Ncalc = 1.58 - 1.6

Optical Data:

Biaxial (-), a=1.598, b=1.605, g=1.608, bire=0.0100, 2V(Calc)=66, 2V(Meas)=63-65.

Calculated Properties of Brianite

Electron Density:

Bulk Density (Electron Density)=3.09 gm/cc
note: Specific Gravity of Brianite =3.13 gm/cc.

Fermion Index:

Fermion Index = 0.0084781832
Boson Index = 0.9915218168

Photoelectric:

PE_Brianite= 3.06 barns/electron
U=PE_Brianite x rElectron Density= 9.43 barns/cc.

Radioactivity:

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

Brianite Classification

Dana Class:

38.01.07.01 (38)Anhydrous Phosphates, etc

(38.01)A+ B++ XO4

(38.01.07)Dana Group

38.01.07.01 Brianite Na2CaMg(PO4)2 P 2₁/a 2/m

Strunz Class:

08.AC.30 08 - PHOSPHATES, ARSENATES, VANADATES

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

08.AC -With medium-sized and large cations

08.AC.30 Brianite Na2CaMg(PO4)2 P 2₁/a 2/m

Other Brianite Information

References:

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

See Also:

Links to other databases for Brianite :
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

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

Brianite

Na2CaMg(PO4)2
Dana No: 38.01.07.01 Strunz No: 08.AC.30
Locality:

Notes:

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