Eggletonite Mineral Data

Advertisment

Our Mission is Simple: RMS will be the go-to portal for all mineral, gem and rock shows in the USA

McDougall Minerals sells high-quality mineral specimens from all over the world to collectors of all levels, from beginners to connoisseurs

Weinrich Minerals, A Dealer in Fine Mineral Specimens - Since 1989. We buy collections and single high quality specimens.

John Betts - Fine Minerals, New York. Dealers of Fine Minerals and Natural Crystal Clusters since 1989. We buy rock collections, we buy gem collections, we buy mineral collections.

General Eggletonite Information

Chemical Formula:

Na2Mn8[Si11AlO29](OH)7•11(H2O)

Composition:

Molecular Weight = 1,602.61 gm

Sodium 2.87 % Na 3.87 % Na₂O

Manganese 27.42 % Mn 35.41 % MnO

Aluminum 1.68 % Al 3.18 % Al₂O₃

Silicon 19.28 % Si 41.24 % SiO₂

Hydrogen 1.82 % H 16.30 % H₂O

Oxygen 46.92 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₂Mn²⁺₈Si₁₁AlO₂₉(OH)₇•11(H₂O)

Environment:

Miarolitic cavities in nepheline syenite. Probably isostructural with ganophyllite.

IMA Status:

Approved IMA 1984

Locality:

Big Rock Quarry, Little Rock, Pulaski County, Arkansas, USA. Link to MinDat.org Location Data.

Name Origin:

Named for R. A. Eggleton, Australian National University.

Name Pronunciation:

Eggletonite + Pronunciation

Eggletonite Image

Images:

Eggletonite

Comments: Brown micro crystals of eggletonite in syenite.
Location: 3M Quarry, Little Rock, Pulaski County, Arkansas, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Eggletonite Crystallography

Axial Ratios:

a:b:c =0.4048:1:1.8221

Cell Dimensions:

a = 5.554, b = 13.72, c = 25, Z = 2; beta = 93.95° V = 1,900.50 Den(Calc)= 2.80

Crystal System:

MonoclinicSpace Group: Ia or I2/a

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

By Intensity(I/I_o): 2.694(1), 12(1), 2.598(0.55),

Physical Properties of Eggletonite

Cleavage:

{001} Perfect

Color:

Golden brown.

Density:

2.76

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

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

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Hardness:

3-4 - Calcite-Fluorite

Luster:

Vitreous (Glassy)

Streak:

light brown

Optical Properties of Eggletonite

Gladstone-Dale:

CI meas= 0.045 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.059 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2117,KPDmeas= 0.2147,KC= 0.2249
Ncalc = 1.62 - 1.63

Optical Data:

Biaxial (-), a=1.566, b=1.606, g=1.606, bire=0.0400, 2V(Calc)=0, 2V(Meas)=9.

Calculated Properties of Eggletonite

Electron Density:

Bulk Density (Electron Density)=2.73 gm/cc
note: Specific Gravity of Eggletonite =2.76 gm/cc.

Fermion Index:

Fermion Index = 0.0092304868
Boson Index = 0.9907695132

Photoelectric:

PE_Eggletonite= 7.73 barns/electron
U=PE_Eggletonite x rElectron Density= 21.13 barns/cc.

Radioactivity:

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

Eggletonite Classification

Dana Class:

74.01.02.02 (74)Phyllosilicate Modulated Layers

(74.01)with joined islands

(74.01.02)Ganophyllite group

74.01.02.01 Ganophyllite (K,Na)2(Mn,Al,Mg)8(Si,Al)12O29(OH)7•8-9(H2O) A2/a 2/m

74.01.02.02 Eggletonite Na2Mn8[Si11AlO29](OH)7•11(H2O) Ia or I2/a Mono

74.01.02.03 Tamaite! (Ca,K,Ba,Na)3-4Mn24(Si,Al)40(O,OH)112•21(H2O) P 2₁/a 2/m

Strunz Class:

09.EG.30 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EG -Double nets with 6-membered and larger rings

09.EG.30 Eggletonite Na2Mn8[Si11AlO29](OH)7•11(H2O) Ia or I2/a Mono

09.EG.30 Ganophyllite (K,Na)2(Mn,Al,Mg)8(Si,Al)12O29(OH)7•8-9(H2O) A2/a 2/m

09.EG.30 Tamaite! (Ca,K,Ba,Na)3-4Mn24(Si,Al)40(O,OH)112•21(H2O) P 2₁/a 2/m

Other Eggletonite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Eggletonite :
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 Eggletonite using:

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

Visit our Advertisers for Eggletonite :

Dakota Matrix Minerals Google Search for Eggletonite
John Betts Fine Minerals Search for Eggletonite
McDougall Minerals Google Search for Eggletonite
Rock and Mineral Shows Google Search for Eggletonite
Weinrich Minerals, Inc. Google Search for Eggletonite

Ask about Eggletonite 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 Eggletonite Specimen Label here :

Eggletonite

Na2Mn8[Si11AlO29](OH)7•11(H2O)
Dana No: 74.01.02.02 Strunz No: 09.EG.30
Locality:

Notes: