Foitite Mineral Data

General Foitite Information

Chemical Formula:

[ ]Na<0.5(Fe++,Al)3Al6Si6O18(BO3)3(OH)4

Composition:

Molecular Weight = 1,031.73 gm

Sodium 2.23 % Na 3.00 % Na₂O

Aluminum 17.65 % Al 33.35 % Al₂O₃

Iron 12.18 % Fe 17.41 % Fe₂O₃

Silicon 16.33 % Si 34.94 % SiO₂

Boron 3.14 % B 10.12 % B₂O₃

Hydrogen 0.39 % H 3.49 % H₂O

Oxygen 48.07 % O

______ ______

100.00 % 102.33 % = TOTAL OXIDE

Empirical Formula:

NaFe³⁺_2.25Al_6.75Si₆O₁₈(BO₃)₃(OH)₄

Environment:

Late-stage granitic pegmatite.

IMA Status:

Approved IMA 1993 (Dana # Changed)

Locality:

White Queen mine, Pala, San Diego County, California, USA. Link to MinDat.org Location Data.

Name Origin:

Named for Franklin F. Foit, Jr. (1942-), mineralogist, Washington State Univerisity, Washington, USA.

Name Pronunciation:

Foitite

Synonym:

Foitite - (61.3.1.1)

ICSD 74012

IMA1992-034

PDF 46-1460

Tourmaline

Foitite Image

Images:

Foitite

Comments: Dark greenish-black termination of foitite on pinkish elbaite.
Location: Dobra Voda, Moravia, Zapadocesky, Czech Republic. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Foitite Crystallography

Axial Ratios:

a:c = 1:0.44629

Cell Dimensions:

a = 15.967, c = 7.126, Z = 3; V = 1,573.34 Den(Calc)= 3.27

Crystal System:

Trigonal - Ditrigonal Pyramidal H-M Symbol (3m) Space Group: R 3m

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

By Intensity(I/I_o): 2.573(1), 3.452(0.91), 6.338(0.84),

Physical Properties of Foitite

Cleavage:

None

Color:

Bluish black.

Density:

3.17

Diaphaneity:

Translucent to Opaque

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Habit:

Striated - Parallel lines on crystal surface or cleavage face.

Hardness:

7 - Quartz

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Streak:

gray white

Optical Properties of Foitite

Dichroism (e):

dark blue.

Dichroism (w):

pale lavender.

Gladstone-Dale:

CI meas= 0.127 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.154 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1997,KPDmeas= 0.206,KC= 0.2359
Ncalc = 1.75 - 1.77

Optical Data:

Uniaxial (-), e=1.642, w=1.664, bire=0.0220.

Calculated Properties of Foitite

Electron Density:

Bulk Density (Electron Density)=3.12 gm/cc
note: Specific Gravity of Foitite =3.17 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Foitite= 4.82 barns/electron
U=PE_Foitite x rElectron Density= 15.04 barns/cc.

Radioactivity:

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

Foitite Classification

Dana Class:

61.03a.01.01 (61)Cyclosilicate Six-Membered Rings

(61.03a)with borate groups (Alkali-Deficient Tourmaline Subgroup)

(61.03a.01)Foitite Subgroup

61.03a.01.01 Foitite! []Na<0.5(Fe,Al)3Al6Si6O18(BO3)3(OH)4 R 3m 3m

61.03a.01.02 Magnesiofoitite! [](Mg2Al)Al6(Si6O18)(BO3)3(OH)4 R 3m 3m

61.03a.01.03 Rossmanite! []LiAl2Al6(Si6O18)(BO3)3(OH)4 R 3m 3m

Strunz Class:

09.CK.05 09 - SILICATES (Germanates)

09.C - Cyclosilicates

09.CK -[Si6O18]12- 6-membered single rings, with insular complex anions

09.CK.05 Chromdravite! NaMg3(Cr,Fe)6(BO3)3Si6O18(OH)4 R 3m 3m

09.CK.05 Feruvite! (Ca,Na)(Fe,Mg,Ti)3(Al,Mg,Fe)6(BO3)3Si6O18(OH)4 R 3m 3m

09.CK.05 Dravite NaMg3Al6(BO3)3Si6O18(OH)4 R 3m 3m

09.CK.05 Buergerite! NaFe3Al6(BO3)3Si6O21F R 3m 3m

09.CK.05 Foitite! []Na<0.5(Fe,Al)3Al6Si6O18(BO3)3(OH)4 R 3m 3m

09.CK.05 Liddicoatite! Ca(Li,Al)3Al6(BO3)3Si6O18(O,OH,F)4 R 3m 3m

09.CK.05 Elbaite Na(Li,Al)3Al6(BO3)3Si6O18(OH)4 R 3m 3m

09.CK.05 Rossmanite! []LiAl2Al6(Si6O18)(BO3)3(OH)4 R 3m 3m

09.CK.05 Olenite! NaAl3Al6(BO3)3(Si6O18)(O,OH)4 R 3m 3m

09.CK.05 Povondraite! (Na,K)(Fe,Fe)3(Fe,Mg,Al)6(BO3)3Si6O18(OH)4 R 3m 3m

09.CK.05 Schorl NaFe3Al6(BO3)3Si6O18(OH)4 R 3m 3m

09.CK.05 Uvite (Ca,Na)(Mg,Fe)3Al5Mg(BO3)3Si6O18(OH,F)4 R 3m 3m

09.CK.05 Vanadiumdravite! NaMg3V6(Si6O18)(BO3)3(OH)4 R 3m 3m

09.CK.05 Magnesiofoitite! [](Mg2Al)Al6(Si6O18)(BO3)3(OH)4 R 3m 3m

09.CK.05 Hydroxyuvite! CaMg3(Al5Mg)(Si6O18)(BO3)3(OH)3(OH) R 3m 3m

09.CK.05 Schorl-(F)! NaFe3Al6Si6O18)(BO3)3(OH)3(F,OH) R 3m 3m

Other Foitite Information

References:

NAME( Dana8) PHYS. PROP.(Am.Min.,78:1299) OPTIC PROP.(Am.Min.,Vol.78,p1299-1303,1993)

See Also:

Links to other databases for Foitite :
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 Foitite Specimen Label here :

Foitite

[ ]Na<0.5(Fe++,Al)3Al6Si6O18(BO3)3(OH)4
Dana No: 61.03a.01.01 Strunz No: 09.CK.05
Locality:

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