Rokuhnite Mineral Data

General Rokuhnite Information

Chemical Formula:

Fe++Cl2•(H2O)

Composition:

Molecular Weight = 144.77 gm

Iron 38.58 % Fe 49.63 % FeO

Hydrogen 1.39 % H 12.44 % H₂O

Chlorine 48.98 % Cl 48.98 % Cl

- % Cl -11.05 % -O=Cl₂

Oxygen 11.05 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺Cl₂•(H₂O)

Environment:

Secondary mineral in fissures in earlier potassium-rich salt beds.

IMA Status:

Approved IMA 1980

Locality:

Salzdetfurth potash mine, Hamelyn, Lower Saxony, Germany. Link to MinDat.org Location Data.

Name Origin:

Named for Robert Kï¿½uhn (1911- ), German mineralogist, Kaliforschungs-Institut der Kali und Salz AG, Hannover, Germany.

Name Pronunciation:

Rokuhnite + Pronunciation

Synonym:

Rokuehnite

Rokuhnite Image

Images:

Rokuhnite Carnallite

Comments: Reddish brown rokuhnite, with carnallite (deliquescent).
Location: Salzdetfurth Mine, Hildesheim, near Hanover, Niedersachsen, Germany. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Rokuhnite Crystallography

Axial Ratios:

a:b:c =0.8744:1:0.4301

Cell Dimensions:

a = 7.396, b = 8.458, c = 3.638, Z = 2; beta = 97.68° V = 225.54 Den(Calc)= 2.13

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): 5.53(1), 2.762(0.7), 4.228(0.6),

Physical Properties of Rokuhnite

Color:

Colorless.

Density:

2.35

Diaphaneity:

Transparent

Optical Properties of Rokuhnite

Optical Data:

Biaxial (+), a=1.605, b=1.633, g=1.702, bire=0.0970, 2V(Calc)=68, 2V(Meas)=64.

Calculated Properties of Rokuhnite

Electron Density:

Bulk Density (Electron Density)=2.06 gm/cc
note: Specific Gravity of Rokuhnite =2.13 gm/cc.

Fermion Index:

Fermion Index = 0.0082334572
Boson Index = 0.9917665428

Photoelectric:

PE_Rokuhnite= 14.84 barns/electron
U=PE_Rokuhnite x rElectron Density= 30.58 barns/cc.

Radioactivity:

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

Rokuhnite Classification

Dana Class:

09.02.04.01 (09)Anhydrous and Hydrated Halides

(09.02)where A (X)2

(09.02.04)Dana Group

09.02.04.01 Rokuhnite FeCl2•(H2O) C 2/m 2/m

Strunz Class:

03.BB.10 03 - HALIDES

03.B - Simple Halides, with H2O

03.BB -M:X = 1:2

03.BB.10 Rokuhnite FeCl2•(H2O) C 2/m 2/m

Other Rokuhnite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Rokuhnite :
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

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

Rokuhnite

Fe++Cl2•(H2O)
Dana No: 09.02.04.01 Strunz No: 03.BB.10
Locality:

Notes:

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