Magadiite Mineral Data

General Magadiite Information

Chemical Formula:

NaSi7O13(OH)3•4(H2O)

Composition:

Molecular Weight = 550.66 gm

Sodium 4.17 % Na 5.63 % Na₂O

Silicon 35.70 % Si 76.38 % SiO₂

Hydrogen 2.01 % H 17.99 % H₂O

Oxygen 58.11 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

NaSi₇O₁₃(OH)₃•4(H₂O)

Environment:

Associated with other rare alkalic minerals in brines with high Ph and silica content.

IMA Status:

Approved IMA 1967

Locality:

Lake Magadi, Olduvai Gorge, Kenya. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Magadiite + Pronunciation

Magadiite Image

Images:

Magadiite Rhodesite

Comments: Earth pale tan massive magadiite with dark yellow crystalline rhodesite.
Location: East Fork, Trinity River, Trinity County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Magadiite Crystallography

Axial Ratios:

a:b:c =1:1:2.1641

Cell Dimensions:

a = 7.25, b = 7.25, c = 15.69, Z = 2; beta = 96.8° V = 818.90 Den(Calc)= 2.23

Crystal System:

Monoclinic Space Group: Unk

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

By Intensity(I/I_o): 15.41(1), 3.435(0.8), 3.146(0.5),

Physical Properties of Magadiite

Color:

White.

Diaphaneity:

Transparent

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Habit:

Platy - Sheet forms (e.g. micas).

Habit:

Powdery - Forms a loose, poorly-coherent pulverulent mass.

Hardness:

2 - Gypsum

Luminescence:

Fluorescent, Short UV=yellow-white, Long UV=yellow-white.

Luster:

Vitreous - Dull

Streak:

white

Optical Properties of Magadiite

Gladstone-Dale:

CI calc= 0.087 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2108,KC= 0.2307
Ncalc = 1.51

Optical Data:

Biaxial (?), a=1.47

Calculated Properties of Magadiite

Electron Density:

Bulk Density (Electron Density)=2.27 gm/cc
note: Specific Gravity of Magadiite =2.23 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Magadiite= 1.48 barns/electron
U=PE_Magadiite x rElectron Density= 3.36 barns/cc.

Radioactivity:

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

Magadiite Classification

Dana Class:

78.07.12.01 (78)Unclassified silicates

(78.07)wholly unclassified silicates

(78.07.12)Dana Group

78.07.12.01 Magadiite NaSi7O13(OH)3•4(H2O) Unk Mono

Strunz Class:

09.EA.20 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EA -Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings

09.EA.20 Magadiite NaSi7O13(OH)3•4(H2O) Unk Mono

Other Magadiite Information

References:

NAME( Dana8) PHYS. PROP.(www.saint-hilaire.ca) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Magadiite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - GeoScienceWorld
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info

Search for Magadiite using:

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

Visit our Advertisers for Magadiite :

Ask about Magadiite 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 Magadiite Specimen Label here :

Magadiite

NaSi7O13(OH)3•4(H2O)
Dana No: 78.07.12.01 Strunz No: 09.EA.20
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.