Manganhumite Mineral Data

General Manganhumite Information

Chemical Formula:

(Mn,Mg)7(SiO4)3(OH)2

Composition:

Molecular Weight = 641.22 gm

Magnesium 6.63 % Mg 11.00 % MgO

Manganese 44.98 % Mn 58.08 % MnO

Silicon 13.14 % Si 28.11 % SiO₂

Hydrogen 0.31 % H 2.81 % H₂O

Oxygen 34.93 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺_5.25Mg_1.75(SiO₄)₃(OH)₂

Environment:

A late-stage skarn mineral formed in recrystallized limestone banded between layers of manganese ore minerals

IMA Status:

Approved IMA 1978

Locality:

Brattfors mine, Nordmark, and at Langban, Varmland, Sweden. Link to MinDat.org Location Data.

Name Origin:

Named for manganese in the composition and relation to humite.

Name Pronunciation:

Manganhumite + Pronunciation

Synonym:

ICSD 200351

PDF 29-866

Manganhumite Crystallography

Axial Ratios:

a:b:c =0.4551:1:2.0272

Cell Dimensions:

a = 4.815, b = 10.58, c = 21.448, Z = 4; V = 1,092.62 Den(Calc)= 3.90

Crystal System:

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

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

By Intensity(I/I_o): 1.7823(1), 3.393(0.89), 2.513(0.79),

Physical Properties of Manganhumite

Cleavage:

{010} Perfect

Color:

Brown, Brown orange, Light orange.

Density:

3.83

Diaphaneity:

Transparent to Translucent

Hardness:

4 - Fluorite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Manganhumite

Gladstone-Dale:

CI meas= 0.088 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.104 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1831,KPDmeas= 0.1864,KC= 0.2044
Ncalc = 1.78 - 1.8

Optical Data:

Biaxial (+), a=1.707, b=1.712, g=1.723, bire=0.0160, 2V(Calc)=70, 2V(Meas)=37.

Calculated Properties of Manganhumite

Electron Density:

Bulk Density (Electron Density)=3.68 gm/cc
note: Specific Gravity of Manganhumite =3.83 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Manganhumite= 12.22 barns/electron
U=PE_Manganhumite x rElectron Density= 45.01 barns/cc.

Radioactivity:

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

Manganhumite Classification

Dana Class:

52.03.02c.03 (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O

(52.03)with cations in [6] coordination only

(52.03.02c)Humite group (Humite series)

52.03.02c.01 Humite (Mg,Fe)7(SiO4)3(F,OH)2 P nma 2/m 2/m 2/m

52.03.02c.02 Leucophoenicite Mn7(SiO4)3(OH)2 P 2₁/a 2/m

52.03.02c.03 Manganhumite (Mn,Mg)7(SiO4)3(OH)2 Pbnm 2/m 2/m 2/m

52.03.02c.04 Chegemite! Ca7(SiO4)3(OH)2 Pbnm 2/m 2/m 2/m

Strunz Class:

09.AF.50 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AF -Nesosilicates with additional anions;

09.AF.50 Manganhumite (Mn,Mg)7(SiO4)3(OH)2 Pbnm 2/m 2/m 2/m

09.AF.50 Humite (Mg,Fe)7(SiO4)3(F,OH)2 P nma 2/m 2/m 2/m

09.AF.50 Chegemite! Ca7(SiO4)3(OH)2 Pbnm 2/m 2/m 2/m

Other Manganhumite 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 Manganhumite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Franklin Minerals(Dunn)
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

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

Manganhumite

(Mn,Mg)7(SiO4)3(OH)2
Dana No: 52.03.02c.03 Strunz No: 09.AF.50
Locality:

Notes:

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