Bobfergusonite Mineral Data

General Bobfergusonite Information

Chemical Formula:

Na2Mn++5Fe+++Al(PO4)6

Composition:

Molecular Weight = 973.33 gm

Sodium 4.72 % Na 6.37 % Na₂O

Manganese 28.22 % Mn 36.44 % MnO

Aluminum 2.77 % Al 5.24 % Al₂O₃

Iron 5.74 % Fe 8.20 % Fe₂O₃

Phosphorus 19.09 % P 43.75 % P₂O₅

Oxygen 39.45 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₂Mn²⁺₅Fe³⁺Al(PO₄)₆

Environment:

An uncommon primary mineral in the intermediate zone of a granite pegmatite enriched in manganese and fluorine.

IMA Status:

Approved IMA 1986

Locality:

From the Gotcha claim, on an island in Cross Lake, Manitoba, Canada. Link to MinDat.org Location Data.

Name Origin:

To honor Emeritus Professor Robert Bury Ferguson (1920- ), Canadian mineralogist, University of Manitoba, Winnipeg, Canada, especially for his contributions to pegmatite mineralogy.

Name Pronunciation:

Bobfergusonite + Pronunciation

Synonym:

ICSD 63261

IMA1984-072

PDF 40-509

Bobfergusonite Image

Images:

Bobfergusonite

Comments: Opaque dark green to brown crystalline bobfergusonite in pegmatite.
Location: Cross Lake, Manitoba, Canada. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Bobfergusonite Crystallography

Axial Ratios:

a:b:c =1.0229:1:0.884

Cell Dimensions:

a = 12.773, b = 12.486, c = 11.038, Z = 4; beta = 97.15° V = 1,746.69 Den(Calc)= 3.70

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/n

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

By Intensity(I/I_o): 3.05(1), 2.08(0.67), 2.87(0.66),

Physical Properties of Bobfergusonite

Cleavage:

{010} Perfect

Color:

Greenish brown, Reddish brown.

Density:

3.54

Diaphaneity:

Transparent to Subopaque

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Hardness:

4 - Fluorite

Luster:

Resinous

Streak:

yellowish brown

Optical Properties of Bobfergusonite

Gladstone-Dale:

CI meas= 0.011 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.054 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1898,KPDmeas= 0.1984,KC= 0.2006
Ncalc = 1.71 - 1.74

Optical Data:

Biaxial (+), a=1.694, b=1.698, g=1.715, bire=0.0210, 2V(Calc)=54, 2V(Meas)=46.4.

Calculated Properties of Bobfergusonite

Electron Density:

Bulk Density (Electron Density)=3.40 gm/cc
note: Specific Gravity of Bobfergusonite =3.54 gm/cc.

Fermion Index:

Fermion Index = 0.0014057662
Boson Index = 0.9985942338

Photoelectric:

PE_{Bobfergusonite}= 10.07 barns/electron
U=PE_{Bobfergusonite} x rElectron Density= 34.27 barns/cc.

Radioactivity:

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

Bobfergusonite Classification

Dana Class:

38.02.04.05 (38)Anhydrous Phosphates, etc

(38.02)(A+ B++)5 (XO4)3

(38.02.04)Alluaudite-Wyllieite Group (Wyllieite Subgroup)

38.02.04.01 Ferrowyllieite (Na,Ca,Mn)(Fe,Mn)(Fe,Fe,Mg)Al(PO4)3 P 2₁/n 2/m

38.02.04.02 Wyllieite (Na,Ca,Mn)(Mn,Fe)(Fe,Fe,Mg)Al(PO4)3 P 2₁/n 2/m

38.02.04.03 Rosemaryite (Na,Ca,Mn)(Mn,Fe)(Fe,Fe,Mg)Al(PO4)3 P 2₁/n 2/m

38.02.04.04 Qingheiite Na2(Mn,Mg,Fe)(Al,Fe)(PO4)3 P 2₁/n 2/m

38.02.04.05 Bobfergusonite Na2Mn5FeAl(PO4)6 P 2₁/n 2/m

38.02.04.06 Bradaczekite! NaCu4(AsO4)3 C 2/c 2/m

38.02.04.07 Ferrorosemaryite! []NaFeFeAl(PO4)3 P 2₁/n 2/m

Strunz Class:

08.AC.15 08 - PHOSPHATES, ARSENATES, VANADATES

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

08.AC -With medium-sized and large cations

08.AC.15 Bobfergusonite Na2Mn5FeAl(PO4)6 P 2₁/n 2/m

08.AC.15 Ferrowyllieite (Na,Ca,Mn)(Fe,Mn)(Fe,Fe,Mg)Al(PO4)3 P 2₁/n 2/m

08.AC.15 Qingheiite Na2(Mn,Mg,Fe)(Al,Fe)(PO4)3 P 2₁/n 2/m

08.AC.15 Rosemaryite (Na,Ca,Mn)(Mn,Fe)(Fe,Fe,Mg)Al(PO4)3 P 2₁/n 2/m

08.AC.15 Wyllieite (Na,Ca,Mn)(Mn,Fe)(Fe,Fe,Mg)Al(PO4)3 P 2₁/n 2/m

08.AC.15 Ferrorosemaryite! []NaFeFeAl(PO4)3 P 2₁/n 2/m

Other Bobfergusonite 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 Bobfergusonite :
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
14 - WWW-MINCRYST

Search for Bobfergusonite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Bobfergusonite :

Ask about Bobfergusonite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Bobfergusonite

Na2Mn++5Fe+++Al(PO4)6
Dana No: 38.02.04.05 Strunz No: 08.AC.15
Locality:

Notes:

Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.