Brammallite Mineral Data (original) (raw)

General Brammallite Information

Help on Chemical Formula: Chemical Formula:

(Na,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)]

Help on Composition: Composition:

Molecular Weight = 391.86 gm

Sodium 3.87 % Na 5.22 % Na2O

Magnesium 3.72 % Mg 6.17 % MgO

Aluminum 13.77 % Al 26.02 % Al2O3

Iron 1.43 % Fe 1.83 % FeO

Silicon 21.50 % Si 46.00 % SiO2

Hydrogen 1.28 % H 11.47 % H2O

Oxygen 54.43 % O

______ ______

100.00 % 96.71 % = TOTAL OXIDE

Help on Empirical Formula: Empirical Formula:

Na0.66(H3O)0.33AlMg0.6Fe2+0.1Si3AlO10(OH)2�(H2O)

Help on Environment: Environment:

Believed to be a degradation product of paragonite. Group name for Interlayer-deficient clays.

Help on IMA Status: IMA Status:

Not Approved IMA 1998

Help on Locality: Locality:

Landebie, Dyfed, Wales. Link to MinDat.org Location Data.

Help on Name Origin: Name Origin:

Named in 1943 for Alfred Brammall (1879-?), British gologist and mineralogist.

Help on Name Pronunciation: Name Pronunciation:

Brammallite + Pronunciation Say BRAMMALLITE

Help on Synonym: Synonym:

Hydroparagonite

Sodium hydromica

Sodium illite

Brammallite Image

Click Here for Larger Brammallite Image in a New Browser Window Images:

Brammallite Crystallography

Help on Axial Ratios: Axial Ratios:

a:b:c =0.5746:1:2.1616

Help on Cell Dimensions: Cell Dimensions:

a = 5.12, b = 8.91, c = 19.26, Z = 4; beta = 95.83° V = 874.08 Den(Calc)= 2.98

Help on Crystal System: Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/c

Help on X Ray Diffraction: X Ray Diffraction:

By Intensity(I/Io): 1.485(1), 9.77(1), 3.17(1),4.41(0.9), 2.54(0.9), 4.78(0.8), 2.11(0.6), 2.41(0.6),

Physical Properties of Brammallite

Help on Cleavage: Cleavage:

{001} Perfect

Help on Color: Color:

White.

Help on Density: Density:

2.83 - 2.88, Average = 2.85

Help on Diaphaneity: Diaphaneity:

Translucent

Help on Fracture: Fracture:

Earthy - Dull, clay-like fractures with no visible crystalline affinities, (e.g. howlite).

Help on Habit: Habit:

Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).

Help on Hardness: Hardness:

2.5-3 - Finger Nail-Calcite

Help on Luster: Luster:

Earthy (Dull)

Help on Streak: Streak:

white

Optical Properties of Brammallite

Help on Gladstone-Dale: Gladstone-Dale:

CI meas= 0.065 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.105 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1918,KPDmeas= 0.2002,KC= 0.2142
Ncalc = 1.61 - 1.64

Help on Optical Data: Optical Data:

Biaxial (-), a=1.535-1.57, b=1.555-1.6, g=1.565-1.605, bire=0.0300-0.0350, 2V(Calc)=42-68, 2V(Meas)=5-25. Dispersion none.

Help on Pleochroism (x): Pleochroism (x):

colorless.

Help on Pleochroism (y): Pleochroism (y):

colorless.

Help on Pleochroism (z): Pleochroism (z):

colorless.

Calculated Properties of Brammallite

Help on Electron Density: Electron Density:

Bulk Density (Electron Density)=2.87 gm/cc
note: Specific Gravity of Brammallite =2.86 gm/cc.

Help on Fermion Index: Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Help on Photoelectric: Photoelectric:

PEBrammallite = 1.83 barns/electron
U=PEBrammallite x rElectron Density= 5.23 barns/cc.

Help on Radioactivity: Radioactivity:

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

Brammallite Classification

Help on Dana Class: Dana Class:

71.02.02d.04 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.02)with 2:1 Layers

(71.02.02d)Mica Group (Hydromica subgroup)

71.02.02d.01 Hydrobiotite [K(Mg,Fe)3(Al,Fe)Si3O10(OH,F)2]•[(Mg,Fe,Al)3(Si,Al)4O10(OH)2•4(H2O)] C 2/m 2/m

71.02.02d.02 Illite* (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] C 2/m 2/m

71.02.02d.03 Vermiculite (Mg,Fe,Al)3(Al,Si)4O10(OH)2•4(H2O) C 2/m 2/m

71.02.02d.04 Brammallite* (Na,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] C 2/c 2/m

Help on Strunz Class: Strunz Class:

09.EC.25 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets

09.EC.25 Brammallite* (Na,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] C 2/c 2/m

Other Brammallite Information

Help on References: References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)

Help on See Also: See Also:

Links to other databases for Brammallite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - MinDAT
8 - Mineralienatlas (Deutsch)
9 - Online Mineral Museum
10 - QUT Mineral Atlas
11 - Ruff.Info

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Ask about Brammallite here :
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Print or Cut-and-Paste your Brammallite Specimen Label here :

Brammallite

(Na,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)]
Dana No: 71.02.02d.04 Strunz No: 09.EC.25
Locality:

Notes: