Johninnesite Mineral Data

General Johninnesite Information

Chemical Formula:

Na2Mg4Mn++12(AsO4)2(Si12O35)(OH)6

Composition:

Molecular Weight = 2,079.34 gm

Sodium 2.21 % Na 2.98 % Na₂O

Magnesium 4.68 % Mg 7.75 % MgO

Manganese 31.71 % Mn 40.94 % MnO

Silicon 16.21 % Si 34.67 % SiO₂

Arsenic 7.21 % As 11.05 % As₂O₅

Hydrogen 0.29 % H 2.60 % H₂O

Oxygen 37.70 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₂Mg₄Mn²⁺₁₂(AsO₄)₂Si₁₂O₃₅(OH)₆

Environment:

In low temperature hydrothermal veins cutting metamophosed Fe-Mn ores.

IMA Status:

Approved IMA 1986

Locality:

Kombat mine, located 37 km east of Otavi and 49 km south of Tsumeb in the north-central part of Namibia. Link to MinDat.org Location Data.

Name Origin:

Named for John Innes, mineralogist of the Tsumeb Corporation, for his contributions to the mineralogy of the Tsumeb and Kombat mines.

Name Pronunciation:

Johninnesite + Pronunciation

Synonym:

ICSD 75306

PDF 39-402

Johninnesite Image

Images:

Johninnesite

Comments: Orange crystalline vein of johninnesite in manganese oxide matrix.
Location: Ausserferrera, Val Ferrera, Graubundun, Switzerland. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Johninnesite Crystallography

Axial Ratios:

a:b:c =0.9435:1:0.8694

Cell Dimensions:

a = 10.44, b = 11.065, c = 9.62, Z = 1; alpha = 107.43°, beta = 82.7°, gamma = 111.6° V = 977.82 Den(Calc)= 3.53

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 2.676(1), 3.23(0.6), 9.8(0.6),

Physical Properties of Johninnesite

Cleavage:

{100} Good, {010} Poor

Color:

Yellow brown.

Density:

3.48

Diaphaneity:

Transparent

Fracture:

Conchoidal - Uneven - Uneven fracture producing small, conchoidal fragments.

Habit:

Fibrous - Crystals made up of fibers.

Habit:

Plumose - "Mica-like" minerals forming aggregates of plume-like forms.

Habit:

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

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Vitreous (Glassy)

Streak:

brownish yellow

Optical Properties of Johninnesite

Gladstone-Dale:

CI meas= 0.012 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.017 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1972,KPDmeas= 0.1984,KC= 0.2007
Ncalc = 1.7

Optical Data:

Biaxial (-), a=1.6742, b=1.6968, g=1.6999, bire=0.0257, 2V(Calc)=40, 2V(Meas)=41.9. Dispersion r > v distinct.

Calculated Properties of Johninnesite

Electron Density:

Bulk Density (Electron Density)=3.35 gm/cc
note: Specific Gravity of Johninnesite =3.48 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Johninnesite= 13.75 barns/electron
U=PE_Johninnesite x rElectron Density= 46.11 barns/cc.

Radioactivity:

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

Johninnesite Classification

Dana Class:

69.02.05.01 (69)Inosilicate Chains with Side Branches or Loops

(69.02)with P>2

(69.02.05)Dana Group

69.02.05.01 Johninnesite Na2Mg4Mn12(AsO4)2(Si12O35)(OH)6 P1 1

Strunz Class:

09.DH.70 09 - SILICATES (Germanates)

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

09.DH -Inosilicates with 4-periodic single chains, Si4O12

09.DH.70 Johninnesite Na2Mg4Mn12(AsO4)2(Si12O35)(OH)6 P1 1

Other Johninnesite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(AntBidBlaNic2) OPTIC PROP.(AntBidBlaNic2)

See Also:

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

Johninnesite

Na2Mg4Mn++12(AsO4)2(Si12O35)(OH)6
Dana No: 69.02.05.01 Strunz No: 09.DH.70
Locality:

Notes:

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