Gedrite Mineral Data

General Gedrite Information

Chemical Formula:

[ ]Mg5Al2Si6Al2O22(OH)2

Composition:

Molecular Weight = 783.97 gm

Magnesium 15.50 % Mg 25.71 % MgO

Aluminum 13.77 % Al 26.01 % Al₂O₃

Silicon 21.49 % Si 45.98 % SiO₂

Hydrogen 0.26 % H 2.30 % H₂O

Oxygen 48.98 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg₅Al₂(Si₆Al₂O₂₂)(OH)₂

IMA Status:

Valid Species (Pre-IMA) 1836

Locality:

Heas Valley near Gedres, France. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Gedrite

Synonym:

ICSD 34833

PDF 13-506

Gedrite Image

Images:

Gedrite

Comments: Back prismatic crystalline gedrite in rock.
Location: Schissgruvan, near Ludvika, Dalarna, Kopparberg, Sweden. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Gedrite Magnesiogedrite

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

Gedrite Crystallography

Axial Ratios:

a:b:c =1.0393:1:0.2964

Cell Dimensions:

a = 18.594, b = 17.89, c = 5.304, Z = 4; V = 1,764.36 Den(Calc)= 2.95

Crystal System:

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

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

By Intensity(I/I_o): 3.06(1), 8.27(0.8), 3.27(0.7),8.97(0.5), 2.5(0.4), 3.35(0.4), 3.65(0.4), 4.48(0.4),

Crystal Structure:

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Papike J J , Ross M , American Mineralogist , 55 (1970) p.1945-1972, Gedrites: Crystal structures and intracrystalline cation distributions, sample 001

View Additional jPOWD Structure files for Gedrite
[1]

Physical Properties of Gedrite

Cleavage:

{210} Perfect, {100} Indistinct, {001} Indistinct

Color:

Brown, Brown green, Green, Gray, Gray white.

Density:

3.15 - 3.57, Average = 3.36

Diaphaneity:

Transparent to Subopaque

Habit:

Massive - Fibrous - Distinctly fibrous fine-grained forms.

Hardness:

5.5-6 - Knife Blade-Orthoclase

Luster:

Vitreous - Silky

Streak:

gray white

Optical Properties of Gedrite

Gladstone-Dale:

CI meas= 0.029 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.105 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2307,KPDmeas= 0.2026,KC= 0.2087
Ncalc = 1.62 - 1.75

Optical Data:

Biaxial (-), a=1.671, b=1.681, g=1.69, bire=0.0190, 2V(Calc)=86, 2V(Meas)=75.

Calculated Properties of Gedrite

Electron Density:

Bulk Density (Electron Density)=3.34 gm/cc
note: Specific Gravity of Gedrite =3.36 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Gedrite= 1.58 barns/electron
U=PE_Gedrite x rElectron Density= 5.27 barns/cc.

Radioactivity:

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

Gedrite Classification

Dana Class:

66.01.02.06 (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.DE.05 09 - SILICATES (Germanates)

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

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

09.DE.05 Ferro-anthophyllite []Fe7Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Anthophyllite []Mg7Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Ferrogedrite []Fe5Al2Si6Al2O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Gedrite []Mg5Al2Si6Al2O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Ferroholmquistite [](Li2Fe3Al2)Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Holmquistite [](Li2Mg3Al2)Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Cummingtonite []Mg7Si8O22(OH)2 C 2/m 2/m

09.DE.05 Clinoferroholmquistite [](Li2Fe3Al2)Si8O22(OH)2 C 2/m 2/m

09.DE.05 Grunerite []Fe7Si8O22(OH)2 C 2/m 2/m

09.DE.05 Magnesiocummingtonite (Mg,Fe)7Si8O22(OH)2 C 2/m 2/m

09.DE.05 Manganogrunerite []Mn2Fe5Si8O22(OH) C 2/m 2/m

09.DE.05 Magnesioanthophyllite? (Mg,Fe)7Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Protomangano-ferro-anthophyllite! (Mn,Fe)2(Fe,Mg)5(Si4O11)2(OH)2 Pnmn 2/m 2/m 2/m

09.DE.05 Sodicgedrite NaMg6AlSi6Al2O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Sodic-ferro-anthophyllite! NaFe7Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Sodic-ferrogedrite! NaFe6AlSi6Al2O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Sodicanthophyllite NaMg7Si8O22(OH)2 P nma 2/m 2/m 2/m

09.DE.05 Permanganogrunerite! []Mn4(Fe)3(Si8O22)(OH)2 C 2/m 2/m

09.DE.05 Protoferro-anthophyllite! (Fe,Mn)2(Fe,Mg)5(Si4O11)2(OH)2 Pnmn 2/m 2/m 2/m

09.DE.05 Fluoro-sodic-pedrizite! NaLi2(Mg2Al2Li)S5Si8O22F2 C 2/m 2/m

09.DE.05 Sodic-ferri-ferropedrizite! NaLi2(Fe2Fe3)Si8O22(OH)2 C 2/m 2/m

09.DE.05 Manganocummingtonite Na(Na,Mn)2(Mg4,Fe)5Si8O22(OH)2 C 2/m 2/m

09.DE.05 Protoanthophyllite! (Mg,Fe)7Si8O22(OH)2 Pnmn 2/m 2/m 2/m

09.DE.05 Ferri-clinoferroholmquistite! []Li2(Fe2Fe3)Si8O22(OH)2 C 2/m 2/m

09.DE.05 Sodic-ferripedrizite! Na(LiNa)(Fe2Mg2Li)Si8O22(OH,F)2 C 2/m 2/m

09.DE.05 Ferripedrizite! NaLi2(Fe2Mg2Li)Si8O22(OH)2 C 2/m 2/m

Other Gedrite Information

References:

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

See Also:

Links to other databases for Gedrite :
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
15 - Scandinavian mineral gallery
16 - University of Colorado - Mineral Structure Data
17 - WWW-MINCRYST

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Print or Cut-and-Paste your Gedrite Specimen Label here :

Gedrite

[ ]Mg5Al2Si6Al2O22(OH)2
Dana No: 66.01.02.06 Strunz No: 09.DE.05
Locality:

Notes: