Avogadrite Mineral Data

General Avogadrite Information

Chemical Formula:

(K,Cs)BF4

Composition:

Molecular Weight = 149.35 gm

Cesium 22.25 % Cs 23.59 % Cs₂O

Potassium 19.63 % K 23.65 % K₂O

Boron 7.24 % B 23.31 % B₂O₃

Fluorine 50.88 % F 50.88 % F

- % F -21.42 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

K_0.75Cs_0.25BF₄

Environment:

Sublimate from volcanic fumaroles.

IMA Status:

Valid Species (Pre-IMA) 1926

Locality:

Vesuvius, Italy. Link to MinDat.org Location Data.

Name Origin:

Named for Amedeo Avogadro (1776-1856), Professor of Physics at the University of Turin, Turin, Italy.

Name Pronunciation:

Avogadrite + Pronunciation

Synonym:

ICSD 9875

PDF 16-378

Avogadrite Image

Images:

Ferruccite Avogadrite

Comments: Very small, white crystals of ferrite on massive, yellowish avogadrite.
Location: Vesuvius, Naples, Naples province, Campania, Italy. Scale: Picture size 5 mm.
© Thomas Witzke / Abraxas-Verlag

Images:

Avogadrite Malladrite

Comments: Botryoidal pinkish-white avogadrite with yellow malladrite.
Location: Eruption of 1926, Vesuvius, Campania, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Malladrite Avogadrite

Comments: Yellow-orange crystalline malladrite with pinkish white avogadrite.
Location: Eruption of 1926, Vesuvius, Campania, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Avogadrite Crystallography

Axial Ratios:

a:b:c =1.581:1:1.2824

Cell Dimensions:

a = 8.664, b = 5.48, c = 7.028, Z = 4; V = 333.68 Den(Calc)= 2.97

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: P nma

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

By Intensity(I/I_o): 3.41(1), 3.26(0.8), 3.06(0.75),

Forms:

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Forms: ( 1 0 1) ( 2 1 1) ( 0 1 1) ( 2 1 0) ( 1 0 0) ( 0 0 1)

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Physical Properties of Avogadrite

Color:

Colorless, White, Yellowish, Reddish.

Density:

2.62

Diaphaneity:

Transparent

Habit:

Tabular - Form dimensions are thin in one direction.

Luster:

Vitreous - Greasy

Streak:

colorless

Optical Properties of Avogadrite

Optical Data:

Biaxial (-), a=1.3239, b=1.3245, g=1.3247, bire=0.0008, 2V(Calc)=58, 2V(Meas)=75.

Calculated Properties of Avogadrite

Electron Density:

Bulk Density (Electron Density)=2.74 gm/cc
note: Specific Gravity of Avogadrite =2.97 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Avogadrite= 94.20 barns/electron
U=PE_Avogadrite x r_electron= 258.51 barns/cc.

Radioactivity:

GRapi = 261.75 (Gamma Ray American Petroleum Institute Units)
Concentration of Avogadrite per GRapi unit = 0.38 (%)

Estimated Radioactivity from Avogadrite - barely detectable

Avogadrite Classification

Dana Class:

11.02.02.01 (11)Halide Complexes; Alumino-fluorides

(11.02)where (A)m B (X)4

(11.02.02)Dana Group

11.02.02.01 Avogadrite (K,Cs)BF4 P nma 2/m 2/m 2/m

Strunz Class:

03.CA.10 03 - HALIDES

03.C - Complex Halides

03.CA -Borofluorides

03.CA.10 Avogadrite (K,Cs)BF4 P nma 2/m 2/m 2/m

03.CA.10 Barberiite (NH4)BF4 P nma 2/m 2/m 2/m

Other Avogadrite Information

References:

NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

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

Avogadrite

(K,Cs)BF4
Dana No: 11.02.02.01 Strunz No: 03.CA.10
Locality:

Notes:

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