Johannsenite Mineral Data

Johannsenite Mineral Data +

General Johannsenite Information

Chemical Formula:

CaMnSi2O6

Composition:

Molecular Weight = 247.18 gm

Calcium 16.21 % Ca 22.69 % CaO

Manganese 22.23 % Mn 28.70 % MnO

Silicon 22.72 % Si 48.62 % SiO₂

Oxygen 38.84 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

CaMn²⁺(Si₂O₆)

Environment:

Contact metasomatic rocks.

IMA Status:

Valid Species (Pre-IMA) 1932

Locality:

Empire Zinc Company mine near Hanover, Grant County, New Mexico. Link to MinDat.org Location Data.

Name Origin:

Named after Prof. Albert Johannsen of the University of Chicago.

Synonym:

ICSD 16906

PDF 38-413

Johannsenite Image

Images:

Johannsenite

Comments: Mass of prismatic bluish green colored johannsenite crystals.
Location: N'Chwaning Mine, Kalahari Manganese Field, Northern Cape Province, South Africa. Scale: 7.2 x 4 cm.
© John Veevaert

Images:

Johannsenite

Comments: Rounded glassy prismatic crystals of dark violet brown johannsenite to 1.4 cm. Long.
Location: Consols Mine, Broken Hill, NSW, Australia. Scale: 1.5x1.5x1 cm.
© Richard Dale / Dale Minerals

Johannsenite Crystallography

Axial Ratios:

a:b:c =1.0897:1:0.578

Cell Dimensions:

a = 9.978, b = 9.156, c = 5.293, Z = 4; beta = 105.48° V = 466.02 Den(Calc)= 3.52

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/c

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

By Intensity(I/I_o): 3.048(1), 2.573(0.43), 3.025(0.43),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Freed R L , Peacor D R , American Mineralogist , 52 (1967) p.709-720, Refinement of the crystal structure of johannsenite

Physical Properties of Johannsenite

Cleavage:

[110] Good

Color:

Brown, Brownish black, Greenish, Gray, Gray green.

Density:

3.56

Diaphaniety:

Translucent to opaque

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

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

Hardness:

6 - Orthoclase

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Streak:

greenish gray

Optical Properties of Johannsenite

Gladstone-Dale:

CI meas= 0.011 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2053,KPDmeas= 0.2029,KC= 0.2053

Optical Data:

Biaxial (+), a=1.703-1.716, b=1.711-1.728, g=1.732-1.745, bire=0.0290, 2V(Calc)=64-82, 2V(Meas)=68-70.

Calculated Properties of Johannsenite

Electron Density:

r_electron=3.45 gm/cc
note: r_Johannsenite=3.52 gm/cc.

Fermion Index

Fermion Index = 0.01101
Boson Index = 0.98899

Photoelectric:

PE_Johannsenite= 8.51 barns/electron
U=PE_Johannsenite x r_electron= 29.34 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Johannsenite is Not Radioactive

Johannsenite Classification

Dana Class:

65.1.3a.4 (65)Inosilicate Single-Width Unbranched Chains, W=1

(65.1)with chains P=2

(65.1.3a)C2/c clinopyroxenes (Ca clinopyroxenes)

65.1.3a.1 Diopside CaMgSi2O6 C 2/c 2/m

65.1.3a.2 Hedenbergite CaFeSi2O6 C 2/c 2/m

65.1.3a.3 Augite (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6 C 2/c 2/m

65.1.3a.4 Johannsenite CaMnSi2O6 C 2/c 2/m

65.1.3a.5 Petedunnite Ca(Zn,Mn,Fe,Mg)Si2O6 C 2/c 2/m

65.1.3a.6 Esseneite CaFeAlSiO6 C 2/c 2/m

Strunz Class:

VIII/F.01-70 VIII - Silicates

VIII/F - Inosilicates (chain and band) double chains [Si2O6]4-

VIII/F.01 - Pyroxene group, Clinopyroxene

VIII/F.01-10 Clinoenstatite Mg2Si2O6 P 2₁/c 2/m

VIII/F.01-20 Clinoferrosilite (Fe,Mg)2Si2O6 P 2₁/c 2/m

VIII/F.01-30 Kanoite (Mn,Mg)2Si2O6 P 2₁/c 2/m

VIII/F.01-40 Pigeonite (Mg,Fe,Ca)(Mg,Fe)Si2O6 P 2₁/c 2/m

VIII/F.01-50 Diopside CaMgSi2O6 C 2/c 2/m

VIII/F.01-60 Hedenbergite CaFeSi2O6 C 2/c 2/m

VIII/F.01-70 Johannsenite CaMnSi2O6 C 2/c 2/m

VIII/F.01-80 Petedunnite Ca(Zn,Mn,Fe,Mg)Si2O6 C 2/c 2/m

VIII/F.01-90 Augite (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6 C 2/c 2/m

VIII/F.01-100 Omphacite (Ca,Na)(Mg,Fe,Al)Si2O6 P 2/n 2/m

VIII/F.01-110 Esseneite CaFeAlSiO6 C 2/c 2/m

VIII/F.01-120 Spodumene LiAlSi2O6 C 2/c 2/m

VIII/F.01-130 Jadeite Na(Al,Fe)Si2O6 C 2/c 2/m

VIII/F.01-140 Aegirine NaFeSi2O6 C 2/c 2/m

VIII/F.01-145 Namansilite NaMn(Si2O6) C 2/c 2/m

VIII/F.01-150 Jervisite (Na,Ca,Fe)(Sc,Mg,Fe)Si2O6 C 2/c 2/m

VIII/F.01-160 Natalyite Na(V,Cr)Si2O6 C 2/c 2/m

VIII/F.01-170 Kosmochlor NaCrSi2O6 C 2/c 2/m

Other Johannsenite Information

References:

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

See Also:

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

Search for Johannsenite using:

[ALTAVISTA] [AOL] [All-The-Web] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Johannsenite :

AA Mineral Specimens

B & L Fine Minerals

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

MineralsWeb Fine Minerals

The GeoZone

Wrights Rock Shop

Translate Johannsenite Mineral Data :

Ask about Johannsenite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Johannsenite

CaMnSi2O6
Dana No: 65.1.3a.4 Strunz No: VIII/F.01-70
Locality:

Notes: