Chesterite Mineral Data
General Chesterite Information
Chemical Formula:
(Mg,Fe++)17Si20O54(OH)6
Composition:
Molecular Weight = 2,074.96 gm
Magnesium 14.93 % Mg 24.77 % MgO
Iron 11.44 % Fe 14.72 % FeO
Silicon 27.07 % Si 57.91 % SiO2
Hydrogen 0.29 % H 2.60 % H2 O
Oxygen 46.26 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Mg12.75 Fe2+ 4.25 Si20 O54 (OH)6
Environment:
In black wallrock between chlorite and actinolite zones of a metamorphosed ultramafic body.
IMA Status:
Approved IMA 1978
Locality:
In the Carleton talc quarry, near Chester, Windsor Co., Vermont, USA. Link to MinDat.org Location Data.
Name Origin:
Named for the locality.
Synonym:
ICSD 100659
PDF 31-637
Chesterite Image
Images:
Chesterite Crystallography
Axial Ratios:
a:b:c =0.4108:1:0.1169
Cell Dimensions:
a = 18.614, b = 45.306, c = 5.2966, Z = 4; V = 4,466.76 Den(Calc)= 3.09
Crystal System:
Orthorhombic - Pyramidal H-M Symbol (mm2) Space Group: A21ma
X Ray Diffraction:
By Intensity(I/Io ): 8.609(1), 3.076(0.66), 3.246(0.49),
Physical Properties of Chesterite
Cleavage:
{110} Perfect
Color:
Colorless, Pink brown.
Density:
3.23
Diaphaneity:
Transparent
Hardness:
2-2.5 - Gypsum-Finger Nail
Luster:
Silky - Pearly
Streak:
white
Optical Properties of Chesterite
Gladstone-Dale:
CI meas = 0.056 (Good) - where the CI = (1-KPDmeas /KC ) CI calc = 0.013 (Superior) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2038,KPDmeas = 0.1949,KC = 0.2065 Ncalc = 1.64 - 1.67
Optical Data:
Biaxial (-), a=1.617, b=1.632, g=1.64, bire=0.0230, 2V(Calc)=70, 2V(Meas)=71.
Calculated Properties of Chesterite
Electron Density:
Bulk Density (Electron Density)=3.07 gm/cc note: Specific Gravity of Chesterite =3.09 gm/cc.
Fermion Index:
Fermion Index = 0.03 Boson Index = 0.97
Photoelectric:
PEChesterite = 4.73 barns/electronU=PEChesterite x r Electron Density= 14.51 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Chesterite is Not Radioactive
Chesterite Classification
Dana Class:
68.01.01.01 (68) Inosilicate Structures with Chains of More Than One Width
(68.01) Dana Type
(68.01.01) Dana Group
68.01.01.01 Chesterite (Mg,Fe)17Si20O54(OH)6 A21ma mm2
Strunz Class:
09.DF.05 09 - SILICATES (Germanates)
09.D - Inosilicates* Structural terminology according to Liebau (1985)
09.DF -Inosilicates with 2-periodic multiple chains
09.DF.05 Chesterite (Mg,Fe)17Si20O54(OH)6 A21ma mm2
09.DF.05 Clinojimthompsonite (Mg,Fe)5Si6O16(OH)2 C 2/c 2/m
09.DF.05 Jimthompsonite (Mg,Fe)5Si6O16(OH)2 P bca 2/m 2/m 2/m
Other Chesterite Information
References:
NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
See Also:
Links to other databases for Chesterite :
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 - WWW-MINCRYST
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Print or Cut-and-Paste your Chesterite Specimen Label here :
Chesterite
(Mg,Fe++)17Si20O54(OH)6
Dana No: 68.01.01.01 Strunz No: 09.DF.05
Locality:
Notes:
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