Ferrosilite Mineral Data

General Ferrosilite Information

Chemical Formula:

(Fe++,Mg)2Si2O6

Composition:

Molecular Weight = 232.32 gm

Magnesium 10.46 % Mg 17.35 % MgO

Iron 24.04 % Fe 30.93 % FeO

Silicon 24.18 % Si 51.73 % SiO₂

Oxygen 41.32 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺MgSi₂O₆

Environment:

Found in basic and ultrabasic igneous rocks.

IMA Status:

Valid Species (Pre-IMA) 1935

Locality:

Unspecified locality in Russia. Link to MinDat.org Location Data.

Name Origin:

Named for its composition (Ferrous Silicate).

Name Pronunciation:

Ferrosilite + Pronunciation

Synonym:

ICSD 17055

Orthoferrosilite

PDF 29-721

Ferrosilite Image

Images:

Ferrosilite

Comments: Transparent, brown prismatic blades of ferrosilite crystals on matrix.
Location: Summit Rock, Diamond Lake, Douglas County, Oregon, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Ferrosilite Crystallography

Axial Ratios:

a:b:c =2.0288:1:0.5768

Cell Dimensions:

a = 18.418, b = 9.078, c = 5.237, Z = 8; V = 875.62 Den(Calc)= 3.52

Crystal System:

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

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

By Intensity(I/I_o): 2.91(1), 4.61(0.9), 3(0.8),3.23(0.7), 2.59(0.4), 2.52(0.3), 6.46(0.3), 1.781(0.2),

Physical Properties of Ferrosilite

Cleavage:

{210} Good, {100} Parting

Color:

Colorless, Green, Dark brown, Nearly black.

Density:

3.88 - 4.02, Average = 3.95

Diaphaneity:

Translucent to Opaque

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Vitreous (Glassy)

Streak:

pale brownish gray

Optical Properties of Ferrosilite

Gladstone-Dale:

CI meas= 0.056 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.059 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2123,KPDmeas= 0.1892,KC= 0.2004
Ncalc = 1.71 - 1.81

Optical Data:

Biaxial (+), a=1.71-1.767, b=1.723-1.77, g=1.726-1.788, bire=0.0160-0.0210

Pleochroism (x):

pinkish brown.

Pleochroism (z):

greenish brown.

Calculated Properties of Ferrosilite

Electron Density:

Bulk Density (Electron Density)=3.88 gm/cc
note: Specific Gravity of Ferrosilite =3.95 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Ferrosilite= 8.29 barns/electron
U=PE_Ferrosilite x rElectron Density= 32.13 barns/cc.

Radioactivity:

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

Ferrosilite Classification

Dana Class:

65.01.02.02 (65)Inosilicate Single-Width Unbranched Chains, W=1

(65.01)with chains P=2

(65.01.02)Orthopyroxenes

65.01.02.01 Enstatite Mg2Si2O6 P bca 2/m 2/m 2/m

65.01.02.02 Ferrosilite (Fe,Mg)2Si2O6 P bca 2/m 2/m 2/m

65.01.02.03 Donpeacorite (Mn,Mg)MgSi2O6 P bca 2/m 2/m 2/m

Strunz Class:

09.DA.05 09 - SILICATES (Germanates)

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

09.DA -Inosilicates with 2-periodic single chains, Si2O6; pyroxene family

09.DA.05 Donpeacorite (Mn,Mg)MgSi2O6 P bca 2/m 2/m 2/m

09.DA.05 Akimotoite! (Mg,Fe)SiO3 R 3 3

09.DA.05 Enstatite Mg2Si2O6 P bca 2/m 2/m 2/m

09.DA.05 Ferrosilite (Fe,Mg)2Si2O6 P bca 2/m 2/m 2/m

Other Ferrosilite Information

References:

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

See Also:

Links to other databases for Ferrosilite :
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 - University of Colorado - Mineral Structure Data
16 - WWW-MINCRYST

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

Ferrosilite

(Fe++,Mg)2Si2O6
Dana No: 65.01.02.02 Strunz No: 09.DA.05
Locality:

Notes:

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