Spessartine Mineral Data

General Spessartine Information

Chemical Formula:

Mn++3Al2(SiO4)3

Composition:

Molecular Weight = 495.03 gm

Manganese 33.29 % Mn 42.99 % MnO

Aluminum 10.90 % Al 20.60 % Al₂O₃

Silicon 17.02 % Si 36.41 % SiO₂

Oxygen 38.78 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺₃Al₂(SiO₄)₃

Environment:

Magmatic, metamorphic, and pegmatitic rocks.

IMA Status:

Valid Species (Pre-IMA) 1832

Locality:

Aschaffenburg, Spessart Mountains, Bavaria, Germany Link to MinDat.org Location Data.

Name Origin:

Named after its locality.

Name Pronunciation:

Spessartine + Pronunciation

Synonym:

Spessartite

Spessartine Image

Images:

Spessartine

Comments: Dodecahedral crystal of spessartine garnet on matrix.
Location: Haramosh Mountains, Baltistan, Northern Areas, Pakastan. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Spessartine Crystallography

Cell Dimensions:

a = 11.621, Z = 8; V = 1,569.39 Den(Calc)= 4.19

Crystal System:

Isometric - Hexoctahedral H-M Symbol (4/m 3 2/m) Space Group: I a3d

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

By Intensity(I/I_o): 2.6(1), 1.56(0.4), 1.61(0.3),

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Forms: ( 2 1 1)

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Physical Properties of Spessartine

Cleavage:

{???} Distinct

Color:

Red, Reddish orange, Yellowish brown, Reddish brown, Brown.

Density:

4.18

Diaphaneity:

Transparent to translucent

Fracture:

Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.

Habit:

Crystalline - Fine - Occurs as well-formed fine sized crystals.

Habit:

Lamellar - Thin laminae producing a lamellar structure.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

6.5-7.5

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Resinous

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Spessartine

Gladstone-Dale:

CI meas= 0.058 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.06 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1909,KPDmeas= 0.1914,KC= 0.2031
Ncalc = 1.85

Optical Data:

Isotropic, n=1.8.

Calculated Properties of Spessartine

Electron Density:

Bulk Density (Electron Density)=4.04 gm/cc
note: Specific Gravity of Spessartine =4.18 gm/cc.

Fermion Index:

Fermion Index = 0.0081347864
Boson Index = 0.9918652136

Photoelectric:

PE_Spessartine= 9.50 barns/electron
U=PE_Spessartine x rElectron Density= 38.35 barns/cc.

Radioactivity:

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

Spessartine Classification

Dana Class:

51.04.03a.03 (51)Nesosilicate Insular SiO4 Groups Only

(51.04)with cations in [6] and >[6] coordination

(51.04.03a)Garnet group (Pyralspite series)

51.04.03a.01 Pyrope Mg3Al2(SiO4)3 I a3d 4/m 3 2/m

51.04.03a.02 Almandine Fe3Al2(SiO4)3 I a3d 4/m 3 2/m

51.04.03a.03 Spessartine Mn3Al2(SiO4)3 I a3d 4/m 3 2/m

51.04.03a.04 Knorringite Mg3Cr2(SiO4)3 I a3d 4/m 3 2/m

51.04.03a.05 Majorite Mg3(Fe,Al,Si)2(SiO4)3 I a3d 4/m 3 2/m

51.04.03a.06 Calderite (Mn,Ca)3(Fe,Al)2(SiO4)3 I a3d 4/m 3 2/m

Strunz Class:

09.AD.25 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AD -Nesosilicates without additional anions;

09.AD.25 Almandine Fe3Al2(SiO4)3 I a3d 4/m 3 2/m

09.AD.25 Calderite (Mn,Ca)3(Fe,Al)2(SiO4)3 I a3d 4/m 3 2/m

09.AD.25 Andradite Ca3Fe2(SiO4)3 I a3d 4/m 3 2/m

09.AD.25 Goldmanite Ca3(V,Al,Fe)2(SiO4)3 I a3d 4/m 3 2/m

09.AD.25 Hibschite Ca3Al2(SiO4)3-x(OH)4x(x=0.2-1.5) I a3d 4/m 3 2/m

09.AD.25 Knorringite Mg3Cr2(SiO4)3 I a3d 4/m 3 2/m

09.AD.25 Grossular Ca3Al2(SiO4)3 I a3d 4/m 3 2/m

09.AD.25 Henritermierite Ca3(Mn,Al)2(SiO4)2(OH)4 I 4₁/acd 4/m 2/m 2/m

09.AD.25 Katoite Ca3Al2(SiO4)3-x(OH)4xx=1.5-3 I a3d 4/m 3 2/m

09.AD.25 Majorite Mg3(Fe,Al,Si)2(SiO4)3 I a3d 4/m 3 2/m

09.AD.25 Kimzeyite Ca3(Zr,Ti)2(Si,Al,Fe)3O12 I a3d 4/m 3 2/m

09.AD.25 Morimotoite Ca3TiFeSi3O12 I a3d 4/m 3 2/m

09.AD.25 Pyrope Mg3Al2(SiO4)3 I a3d 4/m 3 2/m

09.AD.25 Spessartine Mn3Al2(SiO4)3 I a3d 4/m 3 2/m

09.AD.25 Schorlomite Ca3(Ti,Fe,Al)2[(Si,Fe,Fe)O4]3 I a3d 4/m 3 2/m

09.AD.25 Uvarovite Ca3Cr2(SiO4)3 I a3d 4/m 3 2/m

09.AD.25 Wadalite Ca6Al5Si2O16Cl3 I 43d 4 3m

09.AD.25 Holtstamite! Ca3(Al,Mn)2(SiO4)2(OH)4 I 4₁/acd 4/m 2/m 2/m

Other Spessartine Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

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Spessartine

Mn++3Al2(SiO4)3
Dana No: 51.04.03a.03 Strunz No: 09.AD.25
Locality:

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