Magnesiogedrite Mineral Data

General Magnesiogedrite Information

Chemical Formula:

(Mg,Fe++)5Al2Si6Al2O22(OH)2

Composition:

Molecular Weight = 847.05 gm

Magnesium 8.61 % Mg 14.27 % MgO

Aluminum 12.74 % Al 24.07 % Al₂O₃

Iron 13.19 % Fe 16.96 % FeO

Silicon 19.89 % Si 42.56 % SiO₂

Hydrogen 0.24 % H 2.13 % H₂O

Oxygen 45.33 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg₃Fe²⁺₂Al₂(Si₆Al₂O₂₂)(OH)₂

Environment:

IMA amphibole commission recommends abandoning this species name.

IMA Status:

Discredited IMA 1998

Locality:

Link to MinDat.org Location Data.

Name Origin:

Named for its composition and the original gederite location at Heas Valley, Gedres, France.

Synonym:

Discredited

Magnesiogedrite Image

Images:

Gedrite Magnesiogedrite

Comments: Dark gray cleavage fragment of magnesiogedrite (gedrite).
Location: Bamble, Telemark, Norway. Scale: See Image.
© Rruff Database

Magnesiogedrite Crystallography

Axial Ratios:

a:b:c =1.0445:1:0.2958

Cell Dimensions:

a = 18.531, b = 17.741, c = 5.249, Z = 4; V = 1,725.65 Den(Calc)= 3.26

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: P nma

Physical Properties of Magnesiogedrite

Cleavage:

{???} Good

Color:

Gray white.

Hardness:

5-6 - Between Apatite and Orthoclase

Streak:

white

Optical Properties of Magnesiogedrite

Gladstone-Dale:

CI calc= 0.071 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1914,KC= 0.206
Ncalc = 1.67

Optical Data:

Biaxial (-), a=1.613, b=1.625, g=1.634, bire=0.0210

Pleochroism (x):

none.

Pleochroism (y):

none.

Pleochroism (z):

none.

Calculated Properties of Magnesiogedrite

Electron Density:

Bulk Density (Electron Density)=3.22 gm/cc
note: Specific Gravity of Magnesiogedrite =3.26 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_{Magnesiogedrite}= 5.22 barns/electron
U=PE_{Magnesiogedrite} x rElectron Density= 16.80 barns/cc.

Radioactivity:

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

Magnesiogedrite Classification

Dana Class:

66.01.02.05 (66)Inosilicate Double-Width Unbranched Chains, W=2

(66.01)with P=2 amphibole configuration

(66.01.02)Dana Group

66.01.02.01 Magnesioanthophyllite? (Mg,Fe)7Si8O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.02 Anthophyllite []Mg7Si8O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.02a Protoanthophyllite! (Mg,Fe)7Si8O22(OH)2 Pnmn 2/m 2/m 2/m

66.01.02.03 Ferro-anthophyllite []Fe7Si8O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.03a Protoferro-anthophyllite! (Fe,Mn)2(Fe,Mg)5(Si4O11)2(OH)2 Pnmn 2/m 2/m 2/m

66.01.02.03b Protomangano-ferro-anthophyllite! (Mn,Fe)2(Fe,Mg)5(Si4O11)2(OH)2 Pnmn 2/m 2/m 2/m

66.01.02.04 Sodicanthophyllite NaMg7Si8O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.04a Sodic-ferro-anthophyllite! NaFe7Si8O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.05 Magnesiogedrite? (Mg,Fe)5Al2Si6Al2O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.06 Gedrite []Mg5Al2Si6Al2O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.07 Ferrogedrite []Fe5Al2Si6Al2O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.07a Sodic-ferrogedrite! NaFe6AlSi6Al2O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.08 Sodicgedrite NaMg6AlSi6Al2O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.09 Magnesioholmquistite Li2(Mg,Fe)3Al2Si8O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.10 Holmquistite [](Li2Mg3Al2)Si8O22(OH)2 P nma 2/m 2/m 2/m

66.01.02.11 Ferroholmquistite [](Li2Fe3Al2)Si8O22(OH)2 P nma 2/m 2/m 2/m

Strunz Class:

09.DD.05 09 - SILICATES (Germanates)

09.D - Inosilicates* Structural terminology according to Liebau (1985)

09.DD -Inosilicates with 2-periodic double chains, Si4O11; amphibole family

09.DD.05 Ferri-clinoholmquistite! []Li2Mg3(Fe3)2(Si8O22)(OH)2 C 2/m 2/m

09.DD.05 Clinoholmquistite? [](Li2Mg3Al2)Si8O22(OH)2 C 2/m 2/m

09.DD.05 Magnesiogedrite? (Mg,Fe)5Al2Si6Al2O22(OH)2 P nma 2/m 2/m 2/m

09.DD.05 Magnesioholmquistite Li2(Mg,Fe)3Al2Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DD.05 Magnesioclinoholmquistite? Li2(Mg,Fe)3Al2Si8O22(OH)2 C 2/m 2/m

Other Magnesiogedrite Information

References:

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

See Also:

Links to other databases for Magnesiogedrite :
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 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info

Search for Magnesiogedrite using:

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

Visit our Advertisers for Magnesiogedrite :

Ask about Magnesiogedrite 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 Magnesiogedrite Specimen Label here :

Magnesiogedrite

(Mg,Fe++)5Al2Si6Al2O22(OH)2
Dana No: 66.01.02.05 Strunz No: 09.DD.05
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.