Grunerite Mineral Data
General Grunerite Information
Chemical Formula:
[ ]Fe++7Si8O22(OH)2
Composition:
Molecular Weight = 1,001.61 gm
Iron 39.03 % Fe 50.21 % FeO
Silicon 22.43 % Si 47.99 % SiO2
Hydrogen 0.20 % H 1.80 % H2 O
Oxygen 38.34 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Fe2+ 7 (Si8 O22 )(OH)2
IMA Status:
Valid Species (Pre-IMA) 1853
Locality:
Link to MinDat.org Location Data.
Name Origin:
Named for Louis Emmanuel Gruner (1809-1883), Swiss-French chemist who analyzed the mineral.
Name Pronunciation:
Grunerite + Pronunciation
Synonym:
Amosite
ICSD 24590
PDF 44-1401
Grunerite Image
Images:
Grunerite Crystallography
Axial Ratios:
a:b:c =0.5252:1:0.2925
Cell Dimensions:
a = 9.57, b = 18.22, c = 5.33, Z = 2; beta = 102.1° V = 908.72 Den(Calc)= 3.66
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
X Ray Diffraction:
By Intensity(I/Io ): 8.33(1), 2.77(0.9), 3.07(0.8),
Physical Properties of Grunerite
Cleavage:
{110} Perfect, {???} Distinct
Color:
Ashen, Brown, Brownish green, Dark gray.
Density:
3.4 - 3.5, Average = 3.45
Diaphaneity:
Translucent to opaque
Fracture:
Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.
Habit:
Columnar - Forms columns
Habit:
Fibrous - Crystals made up of fibers.
Habit:
Massive - Uniformly indistinguishable crystals forming large masses.
Hardness:
5-6 - Between Apatite and Orthoclase
Luminescence:
Non-fluorescent.
Luster:
Vitreous - Pearly
Streak:
colorless
Optical Properties of Grunerite
Gladstone-Dale:
CI meas = -0.004 (Superior) - where the CI = (1-KPDmeas /KC ) CI calc = 0.054 (Good) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.1896,KPDmeas = 0.2011,KC = 0.2003 Ncalc = 1.68 - 1.73
Optical Data:
Biaxial (-), a=1.663-1.686, b=1.68-1.709, g=1.696-1.729, bire=0.0330-0.0430, 2V(Calc)=84-86, 2V(Meas)=90-70. Dispersion r > v.
Pleochroism (x):
colorless, colorless, or pale yellow.
Pleochroism (y):
colorless, pale yellow, or yellowish gray.
Pleochroism (z):
colorless, pale green, pale yellow, or pale greenish yellow.
Calculated Properties of Grunerite
Electron Density:
Bulk Density (Electron Density)=3.36 gm/cc note: Specific Gravity of Grunerite =3.45 gm/cc.
Fermion Index:
Fermion Index = 0.01 Boson Index = 0.99
Photoelectric:
PEGrunerite = 12.52 barns/electronU=PEGrunerite x r Electron Density= 42.08 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Grunerite is Not Radioactive
Grunerite Classification
Dana Class:
66.01.01.03 (66) Inosilicate Double-Width Unbranched Chains, W=2
(66.01) with P=2 amphibole configuration
(66.01.01) Group 1, the Mg-Fe-Mn-Li amphiboles (Monoclinic)
66.01.01.01 Magnesiocummingtonite (Mg,Fe)7Si8O22(OH)2 C 2/m 2/m
66.01.01.02 Cummingtonite []Mg7Si8O22(OH)2 C 2/m 2/m
66.01.01.03 Grunerite []Fe7Si8O22(OH)2 C 2/m 2/m
66.01.01.03b Permanganogrunerite ! []Mn4(Fe)3(Si8O22)(OH)2 C 2/m 2/m
66.01.01.04 Manganocummingtonite Na(Na,Mn)2(Mg4,Fe)5Si8O22(OH)2 C 2/m 2/m
66.01.01.05 Manganogrunerite []Mn2Fe5Si8O22(OH) C 2/m 2/m
66.01.01.06 Magnesioclinoholmquistite ? Li2(Mg,Fe)3Al2Si8O22(OH)2 C 2/m 2/m
66.01.01.07 Clinoholmquistite ? [](Li2Mg3Al2)Si8O22(OH)2 C 2/m 2/m
66.01.01.08 Clinoferroholmquistite [](Li2Fe3Al2)Si8O22(OH)2 C 2/m 2/m
66.01.01.08a Ferri-clinoholmquistite ! []Li2Mg3(Fe3)2(Si8O22)(OH)2 C 2/m 2/m
66.01.01.08b Ferri-clinoferroholmquistite ! []Li2(Fe2Fe3)Si8O22(OH)2 C 2/m 2/m
66.01.01.09 Sodic-ferripedrizite ! Na(LiNa)(Fe2Mg2Li)Si8O22(OH,F)2 C 2/m 2/m
66.01.01.09a Ferripedrizite ! NaLi2(Fe2Mg2Li)Si8O22(OH)2 C 2/m 2/m
66.01.01.09b Sodic-ferri-ferropedrizite ! NaLi2(Fe2Fe3)Si8O22(OH)2 C 2/m 2/m
66.01.01.09c Fluoro-sodic-pedrizite ! NaLi2(Mg2Al2Li)S5Si8O22F2 C 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 Grunerite Information
References:
NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)
See Also:
Links to other databases for Grunerite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - CalTech Mineral Spectroscopy
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - HyperPhysics
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - WWW-MINCRYST
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Grunerite
[ ]Fe++7Si8O22(OH)2
Dana No: 66.01.01.03 Strunz No: 09.DE.05
Locality:
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