Nchwaningite Mineral Data

General Nchwaningite Information

Chemical Formula:

Mn++2SiO3(OH)2•(H2O)

Composition:

Molecular Weight = 237.99 gm

Manganese 46.17 % Mn 59.61 % MnO

Silicon 11.80 % Si 25.25 % SiO₂

Hydrogen 1.69 % H 15.14 % H₂O

Oxygen 40.34 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺₂SiO₃(OH)₂•(H₂O)

Environment:

In a vug in manganese ore.

IMA Status:

Approved IMA 1995

Locality:

The N,chwaning II Mine, Kalahari Manganese Field, Northern Cape Province, Republic of South Africa. Link to MinDat.org Location Data.

Name Origin:

Named for its locality.

Name Pronunciation:

Nchwaningite + Pronunciation

Synonym:

ICSD 80118

IMA1994-002

PDF 47-1869

Nchwaningite Image

Images:

Nchwaningite

Comments: SEM image of acicular, platy nchwaningite crystals. (AmMin, v80:377).
Location: N'chwaning mine, Kalahari manganesefi eld, South Africa. Scale: See Image.
© American Mineralogist

Nchwaningite Crystallography

Axial Ratios:

a:b:c =1.7558:1:0.74

Cell Dimensions:

a = 12.672, b = 7.217, c = 5.341, Z = 4; V = 488.45 Den(Calc)= 3.24

Crystal System:

Orthorhombic - PyramidalH-M Symbol (mm2) Space Group: P ca2₁

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

By Intensity(I/I_o): 3.011(1), 2.456(0.8), 2.547(0.8),

Crystal Structure:

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Nyfeler D , Armbruster T , Dixon R , Bermanec V , American Mineralogist , 80 (1995) p.377-386, Nchwaningite, Mn2SiO3(OH)2.H2O, a new pyroxene-related chain silicate from the, N chwaning mine, Kalahari manganese field, South Africa

Physical Properties of Nchwaningite

Cleavage:

{100} Perfect, {010} Perfect

Color:

Light brown.

Density:

3.19

Diaphaneity:

Transparent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Habit:

Spherical - Spherical, rounded aggregates.

Hardness:

5.5 - Knife Blade

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Nchwaningite

Gladstone-Dale:

CI meas= 0.028 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.043 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2118,KPDmeas= 0.2152,KC= 0.2214
Ncalc = 1.71 - 1.72

Optical Data:

Biaxial (-), a=1.681, b=1.688, g=1.69, bire=0.0090, 2V(Calc)=56, 2V(Meas)=54.4.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Nchwaningite

Electron Density:

Bulk Density (Electron Density)=3.11 gm/cc
note: Specific Gravity of Nchwaningite =3.19 gm/cc.

Fermion Index:

Fermion Index = 0.0057072871
Boson Index = 0.9942927129

Photoelectric:

PE_Nchwaningite= 12.20 barns/electron
U=PE_Nchwaningite x rElectron Density= 37.95 barns/cc.

Radioactivity:

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

Nchwaningite Classification

Dana Class:

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

(65.01)with chains P=2

(65.01.08)Dana Group

65.01.08.01 Nchwaningite Mn2SiO3(OH)2•(H2O) P ca2₁ mm2

Strunz Class:

09.DB.30 09 - SILICATES (Germanates)

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

09.DB -Inosilicates with 2-periodic single chains, Si2O6; Pyroxene-related minerals

09.DB.30 Nchwaningite Mn2SiO3(OH)2•(H2O) P ca2₁ mm2

Other Nchwaningite Information

References:

NAME( MinRec) PHYS. PROP.(Am.Min.,Vol.80,p377-386,1995) OPTIC PROP.(MinRec)

See Also:

Links to other databases for Nchwaningite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - MinDAT
8 - Mineralienatlas (Deutsch)
9 - Online Mineral Museum
10 - QUT Mineral Atlas
11 - Ruff.Info
12 - WWW-MINCRYST

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

Nchwaningite

Mn++2SiO3(OH)2•(H2O)
Dana No: 65.01.08.01 Strunz No: 09.DB.30
Locality:

Notes: