Sellaite Mineral Data

General Sellaite Information

Chemical Formula:

MgF2

Composition:

Molecular Weight = 62.30 gm

Magnesium 39.01 % Mg 64.69 % MgO

Fluorine 60.99 % F 60.99 % F

- % F -25.68 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

MgF₂

Environment:

Bituminous dolomite-anhydrite rock.

IMA Status:

Valid Species (Pre-IMA) 1868

Locality:

Gebroulaz glacier, France. Link to MinDat.org Location Data.

Name Origin:

Named for Quintino Sella (1827-1884), Italian mining engineer and mineralogist.

Name Pronunciation:

Sellaite

Synonym:

ICSD 8121

PDF 41-1443

Sellaite Image

Images:

Sellaite

Comments: Compact, white acicular sellaite crystals.
Location: Clara Mine, Rankach valley, Oberwolfach, Wolfach, Black Forest, Baden-WÃ¼rttemberg, Germany. Scale: 21x16x10 mm.
© John Betts - Fine Minerals

Sellaite Crystallography

Axial Ratios:

a:c = 1:0.66051

Cell Dimensions:

a = 4.66, c = 3.078, Z = 2; V = 66.84 Den(Calc)= 3.10

Crystal System:

Tetragonal - Ditetragonal Dipyramidal H-M Symbol (4/m 2/m 2/m) Space Group: P 4₁/mnm

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

By Intensity(I/I_o): 3.27(1), 2.231(0.95), 1.711(0.75),

Forms:

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

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Physical Properties of Sellaite

Cleavage:

{100} Distinct, {110} Distinct

Color:

Colorless, White.

Density:

2.97 - 3.15, Average = 3.06

Diaphaneity:

Transparent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

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

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Vitreous - Greasy

Streak:

white

Optical Properties of Sellaite

Optical Data:

Uniaxial (+), w=1.378, e=1.39, bire=0.0120.

Calculated Properties of Sellaite

Electron Density:

Bulk Density (Electron Density)=2.99 gm/cc
note: Specific Gravity of Sellaite =3.10 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Sellaite= 1.18 barns/electron
U=PE_Sellaite x rElectron Density= 3.51 barns/cc.

Radioactivity:

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

Sellaite Classification

Dana Class:

09.02.02.01 (09)Anhydrous and Hydrated Halides

(09.02)where A (X)2

(09.02.02)Dana Group

09.02.02.01 Sellaite MgF2 P 4₁/mnm 4/m 2/m 2/m

Strunz Class:

03.AB.15 03 - HALIDES

03.A - Simple Halides, Without H2O

03.AB -M:X = 1:2

03.AB.15 Sellaite MgF2 P 4₁/mnm 4/m 2/m 2/m

Other Sellaite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

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

Sellaite

MgF2
Dana No: 09.02.02.01 Strunz No: 03.AB.15
Locality:

Notes:

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