Franconite Mineral Data

General Franconite Information

Chemical Formula:

Na2Nb4O11•9(H2O)

Composition:

Molecular Weight = 755.74 gm

Sodium 6.08 % Na 8.20 % Na₂O

Niobium 49.17 % Nb 70.34 % Nb₂O₅

Hydrogen 2.40 % H 21.45 % H₂O

Oxygen 42.34 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₂Nb₄O₁₁•9(H₂O)

Environment:

In a dawsonite-bearing sill in vugs.

IMA Status:

Approved IMA 1984

Locality:

Francon Quarry, Montreal Island, Quebec, Canada. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Franconite + Pronunciation

Synonym:

IMA1981-006

Franconite Image

Images:

Franconite

Comments: Irregular to ball-shaped aggregates of silky white franconite on white albite.
Location: Mont St. Hilaire, Quebec, Canada. Scale: Specimen Size 2.5 x 4 cm.
© Diederik Visser

Franconite Crystallography

Axial Ratios:

a:b:c =1.7278:1:0.4945

Cell Dimensions:

a = 22.22, b = 12.86, c = 6.36, Z = 4; beta = 92.23° V = 1,815.99 Den(Calc)= 2.76

Crystal System:

Monoclinic Space Group: Unk

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

By Intensity(I/I_o): 11(1), 5.55(0.7), 4.73(0.6),

Physical Properties of Franconite

Cleavage:

{001} Parting

Color:

White.

Density:

2.72

Diaphaneity:

Transparent to Translucent

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).

Hardness:

4 - Fluorite

Luminescence:

Fluorescent, Short UV=yellow white, Long UV=yellow white.

Luster:

Vitreous - Silky

Streak:

white

Optical Properties of Franconite

Gladstone-Dale:

CI meas= -0.013 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.002 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2766,KPDmeas= 0.2806,KC= 0.2771
Ncalc = 1.75 - 1.76

Optical Data:

Biaxial (-), a=1.72, b=1.78, g=1.79, bire=0.0700

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Franconite

Electron Density:

Bulk Density (Electron Density)=2.66 gm/cc
note: Specific Gravity of Franconite =2.76 gm/cc.

Fermion Index:

Fermion Index = 0.000206839
Boson Index = 0.999793161

Photoelectric:

PE_Franconite= 72.34 barns/electron
U=PE_Franconite x rElectron Density= 192.34 barns/cc.

Radioactivity:

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

Franconite Classification

Dana Class:

08.06.01.01 (08)Multiple Oxides with Nb, Ta, and Ti

(08.06)Dana Type

(08.06.01)Franconite Group

08.06.01.01 Franconite Na2Nb4O11•9(H2O) Unk Mono

08.06.01.02 Hochelagaite (Ca,Na,Sr)Nb4O11•8(H2O) Unk Mono

08.06.01.03 Ternovite! (Mg,Ca)Nb4O11-n(H2O)wheren~10 P 2/m,P 2,Pm Mono

Strunz Class:

04.FM.15 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.F - Hydroxides (without V or U)

04.FM -Hydroxides with H2O � (OH); Unclassified

04.FM.15 Franconite Na2Nb4O11•9(H2O) Unk Mono

04.FM.15 Hochelagaite (Ca,Na,Sr)Nb4O11•8(H2O) Unk Mono

04.FM.15 Ternovite! (Mg,Ca)Nb4O11-n(H2O)wheren~10 P 2/m,P 2,Pm Mono

Other Franconite Information

References:

NAME( Dana8) PHYS. PROP.(www.saint-hilaire.ca) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Franconite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - GeoScienceWorld
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info

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

Franconite

Na2Nb4O11•9(H2O)
Dana No: 08.06.01.01 Strunz No: 04.FM.15
Locality:

Notes:

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