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 % H₂O

Oxygen 46.26 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg_12.75Fe²⁺_4.25Si₂₀O₅₄(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 Magnetite

Comments: Green platy chesterite in black, metallic magnetite.
Location: Near Missoula, Missoula County, Montana, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

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

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

By Intensity(I/I_o): 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:

PE_Chesterite= 4.73 barns/electron
U=PE_Chesterite x rElectron 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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