Bararite Mineral Data

General Bararite Information

Chemical Formula:

(NH4)2SiF6

Composition:

Molecular Weight = 178.15 gm

Silicon 15.76 % Si 33.73 % SiO₂

Hydrogen 4.53 % H - % Calc as (NH₄)₂O

Nitrogen 15.72 % N 29.23 % (NH₄)₂O

Fluorine 63.98 % F 63.98 % F

- % F -26.94 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

(NH₄)₂SiF₆

Environment:

Above a burning coal seam. Dimorphous with cryptohalite, the higher-temperature form.

IMA Status:

Valid Species (Pre-IMA) 1951

Locality:

Bararee colliery, Barari, Jharia coalfield, West Bengal, India. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Bararite

Synonym:

ICSD 18027

PDF 44-1424

Bararite Image

Images:

Bararite Cryptohalite

Comments: White crystalline bararite intermixed with cryptohalite colored yellow by selenium.
Location: Shamokin, Northumberland County, Pennsylvani, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Bararite Crystallography

Axial Ratios:

a:c = 1:0.82812

Cell Dimensions:

a = 5.76, c = 4.77, Z = 1; V = 137.05 Den(Calc)= 2.16

Crystal System:

Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: R 3m

Physical Properties of Bararite

Cleavage:

{0001} Perfect

Color:

White.

Density:

2.152

Hardness:

2.5 - Finger Nail

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Bararite

Optical Data:

Uniaxial (-), e=1.391, w=1.406, bire=0.0150.

Calculated Properties of Bararite

Electron Density:

Bulk Density (Electron Density)=2.18 gm/cc
note: Specific Gravity of Bararite =2.16 gm/cc.

Fermion Index:

Fermion Index = 0.16
Boson Index = 0.84

Photoelectric:

PE_Bararite= 0.97 barns/electron
U=PE_Bararite x rElectron Density= 2.12 barns/cc.

Radioactivity:

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

Bararite Classification

Dana Class:

11.05.02.02 (11)Halide Complexes; Alumino-fluorides

(11.05)where (A)m B (X)6

(11.05.02)Malladrite Group

11.05.02.01 Malladrite Na2SiF6 P 3₂1 3 2

11.05.02.02 Bararite (NH4)2SiF6 R 3m 3 2/m

11.05.02.03 Demartinite! K2[SiF6] P 6₃mc 6mm

Strunz Class:

03.CH.10 03 - HALIDES

03.C - Complex Halides

03.CH -

03.CH.10 Bararite (NH4)2SiF6 R 3m 3 2/m

Other Bararite 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 Bararite :
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

Search for Bararite using:

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

Visit our Advertisers for Bararite :

Ask about Bararite 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 Bararite Specimen Label here :

Bararite

(NH4)2SiF6
Dana No: 11.05.02.02 Strunz No: 03.CH.10
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.