Langbanite Mineral Data

General Langbanite Information

Chemical Formula:

(Mn,Ca,Fe)++4(Mn+++,Fe+++)9Sb+++++Si2O24

Composition:

Molecular Weight = 1,291.77 gm

Calcium 0.93 % Ca 1.30 % CaO

Manganese 47.63 % Mn 21.97 % MnO / 44.00 % Mn₂O₃

Iron 6.05 % Fe 8.65 % Fe₂O₃

Silicon 4.35 % Si 9.30 % SiO₂

Antimony 11.31 % Sb 13.54 % Sb₂O₃

Oxygen 29.73 % O

______ ______

100.00 % 98.76 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺_3.7Ca_0.3Mn³⁺_7.2Fe³⁺_1.4Mn²⁺_0.3Sb_1.2Si₂O₂₄

Environment:

In crystalline limestones and manganese-rich skarns in metamorphosed manganese deposits.

IMA Status:

Valid Species (Pre-IMA) 1887

Locality:

At Langbanshyttan, Vermland, Sweden and the Sjo mines near Orebro in Orebro. Link to MinDat.org Location Data.

Name Origin:

After its locality.

Name Pronunciation:

Langbanite + Pronunciation

Langbanite Image

Images:

Langbanite

Comments: Stout black langbanite crystal in white matrix.
Location: Langban, Varmland, Sweden. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Langbanite Crystallography

Axial Ratios:

a:b:c =0.5766:1:0.5523

Cell Dimensions:

a = 11.561, b = 20.05, c = 11.075, Z = 6; beta = 90.03° V = 2,567.16 Den(Calc)= 5.01

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m

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

By Intensity(I/I_o): 2.55(1), 2.74(0.9), 2.8(0.8),

Physical Properties of Langbanite

Cleavage:

{0001} Good

Color:

Iron black.

Density:

4.91

Diaphaneity:

Opaque

Habit:

Crystalline - Coarse - Occurs as well-formed coarse sized crystals.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

6.5 - Pyrite

Luster:

Metallic

Streak:

grayish black

Optical Properties of Langbanite

Gladstone-Dale:

CI meas= -0.077 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= -0.055 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2665,KPDmeas= 0.2719,KC= 0.2525
Ncalc = 2.24 - 2.27

Optical Data:

Uniaxial (-), e=2.31, w=2.36, bire=0.0500.

Calculated Properties of Langbanite

Electron Density:

Bulk Density (Electron Density)=4.68 gm/cc
note: Specific Gravity of Langbanite =5.01 gm/cc.

Fermion Index:

Fermion Index = 0.003469087
Boson Index = 0.996530913

Photoelectric:

PE_Langbanite= 50.37 barns/electron
U=PE_Langbanite x rElectron Density= 235.82 barns/cc.

Radioactivity:

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

Langbanite Classification

Dana Class:

44.03.04.01 (44)Antimonates

(44.03)with miscellaneous formulae

(44.03.04)Dana Group

44.03.04.01 Langbanite (Mn,Ca,Fe)4(Mn,Fe)9SbSi2O24 C 2/m 2/m

Strunz Class:

09.AG.10 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AG -Nesosilicates with additional anions; cations in > [6] � [6] coordination

09.AG.10 Langbanite (Mn,Ca,Fe)4(Mn,Fe)9SbSi2O24 C 2/m 2/m

Other Langbanite Information

References:

NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic2)

See Also:

Links to other databases for Langbanite :
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 Langbanite Specimen Label here :

Langbanite

(Mn,Ca,Fe)++4(Mn+++,Fe+++)9Sb+++++Si2O24
Dana No: 44.03.04.01 Strunz No: 09.AG.10
Locality:

Notes:

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