Mcgovernite Mineral Data

General Mcgovernite Information

Chemical Formula:

Mn9Mg4Zn2As2Si2O17(OH)14

Composition:

Molecular Weight = 1,438.55 gm

Magnesium 6.76 % Mg 11.21 % MgO

Manganese 34.37 % Mn 44.38 % MnO

Zinc 9.09 % Zn 11.32 % ZnO

Silicon 3.90 % Si 8.35 % SiO₂

Arsenic 10.42 % As 15.98 % As₂O₅

Hydrogen 0.98 % H 8.77 % H₂O

Oxygen 34.48 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺₉Mg₄Zn₂As₂Si₂O₁₇(OH)₁₄

Environment:

Metamorphosed zinc-manganese deposit.

IMA Status:

Valid Species (Pre-IMA) 1927

Locality:

Sterling Hill, Franklin, Sussex Co., New Jersey, USA. Link to MinDat.org Location Data.

Name Origin:

Named for J. J. McGovern (1915-), Franklin miner and mineral collector.

Name Pronunciation:

Mcgovernite + Pronunciation

Mcgovernite Image

Images:

Mcgovernite

Comments: Golden sub-metallic micaceous mcgovernite with black franklinite, red willemite, and white calcite.
Location: Franklin, Sussex County, New Jersey, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Mcgovernite Crystallography

Axial Ratios:

a:c = 1:25

Cell Dimensions:

a = 8.22, c = 205.5, Z = 20; V = 12,025.03 Den(Calc)= 3.97

Crystal System:

Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: R 3c

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

By Intensity(I/I_o): 1.54(1), 2.35(0.6), 2.66(0.6),2.37(0.5), 2.8(0.5), 3.24(0.3), 3.43(0.3), 4.06(0.3),

Physical Properties of Mcgovernite

Cleavage:

{001} Perfect

Color:

Bronze brown, Light brown, Dark reddish brown, Reddish brown.

Density:

3.72

Diaphaneity:

Translucent

Fracture:

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

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Habit:

Micaceous - Platy texture with "flexible" plates.

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Pearly

Streak:

brown

Optical Properties of Mcgovernite

Gladstone-Dale:

CI meas= -0.015 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.048 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1911,KPDmeas= 0.2039,KC= 0.2008
Ncalc = 1.75 - 1.8

Optical Data:

Uniaxial (+), w=1.757, e=1.76, bire=0.0030.

Calculated Properties of Mcgovernite

Electron Density:

Bulk Density (Electron Density)=3.56 gm/cc
note: Specific Gravity of Mcgovernite =3.72 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Mcgovernite= 20.77 barns/electron
U=PE_Mcgovernite x rElectron Density= 74.00 barns/cc.

Radioactivity:

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

Mcgovernite Classification

Dana Class:

43.04.09.01 (43)Compound Phosphates, etc.

(43.04)(Anhydrous Compound Anions With Hydroxyl or Halogen)

(43.04.09)Mcgovernite Group

43.04.09.01 Mcgovernite Mn9Mg4Zn2As2Si2O17(OH)14 R 3c 3 2/m

43.04.09.02 Turtmannite! (Mn,Mg)25.5[(V,As)O4]3(SiO4)3[AsO3]xO5-5x(OH)20x R 3c 3 2/m

Strunz Class:

08.BE.45 08 - PHOSPHATES, ARSENATES, VANADATES

08.B - Phosphates, etc. with Additional Anions, without H2O

08.BE -With only medium-sized cations, (OH, etc.):RO4 > 2:1

08.BE.45 Dixenite CuMn14Fe(AsO3)5(SiO4)2(AsO4)(OH)6 R 3 3

08.BE.45 Hematolite (Mn,Mg,Al)15(AsO3)(AsO4)2(OH)23 R 3 3

08.BE.45 Kraisslite (Mn,Mg)24Zn3Fe(AsO3)2(AsO4)3(SiO4)6(OH)18 P 6₃22 6 2 2

08.BE.45 Mcgovernite Mn9Mg4Zn2As2Si2O17(OH)14 R 3c 3 2/m

08.BE.45 Turtmannite! (Mn,Mg)25.5[(V,As)O4]3(SiO4)3[AsO3]xO5-5x(OH)20x R 3c 3 2/m

08.BE.45 Arakiite! (Zn,Mn)(Mn,Mg)12(Fe,Al)2(AsO3)(AsO4)2(OH)23 Cc m

Other Mcgovernite Information

References:

NAME( Ford32) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)

See Also:

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

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

Mcgovernite

Mn9Mg4Zn2As2Si2O17(OH)14
Dana No: 43.04.09.01 Strunz No: 08.BE.45
Locality:

Notes:

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