Kempite Mineral Data

General Kempite Information

Chemical Formula:

Mn2Cl(OH)3

Composition:

Molecular Weight = 196.35 gm

Manganese 55.96 % Mn 72.26 % MnO

Hydrogen 1.54 % H 13.76 % H₂O

Chlorine 18.06 % Cl 18.06 % Cl

- % Cl -4.07 % -O=Cl₂

Oxygen 24.45 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺₂Cl(OH)₃

Environment:

Oxidized portions of manganese deposits.

IMA Status:

Valid Species (Pre-IMA) 1924

Locality:

Alum Rock Park, 7 miles NE of San Jose, Santa Clara Co. California. Link to MinDat.org Location Data.

Name Origin:

Named for James Furman Kemp (1859-1926), Professor of Geology, Columbia University, New York City, New York, USA.

Name Pronunciation:

Kempite

Kempite Crystallography

Axial Ratios:

a:b:c =0.6817:1:0.7478

Cell Dimensions:

a = 6.49, b = 9.52, c = 7.12, Z = 4; V = 439.91 Den(Calc)= 2.96

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pnam

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

By Intensity(I/I_o): 2.386(1), 5.7(0.8), 5.36(0.7),

Physical Properties of Kempite

Cleavage:

None

Color:

Emerald green.

Density:

2.94

Diaphaneity:

Translucent to Opaque

Habit:

Crystalline - Fine - Occurs as well-formed fine sized crystals.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

3.5 - Copper Penny

Luminescence:

Non-fluorescent.

Magnetism:

Nonmagnetic

Streak:

light green

Optical Properties of Kempite

Gladstone-Dale:

CI meas= 0.043 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.05 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2339,KPDmeas= 0.2355,KC= 0.2462
Ncalc = 1.72 - 1.73

Optical Data:

Biaxial (-), a=1.684, b=1.695, g=1.698, bire=0.0140

Calculated Properties of Kempite

Electron Density:

Bulk Density (Electron Density)=2.81 gm/cc
note: Specific Gravity of Kempite =2.94 gm/cc.

Fermion Index:

Fermion Index = 0.0001196466
Boson Index = 0.9998803534

Photoelectric:

PE_Kempite= 15.66 barns/electron
U=PE_Kempite x rElectron Density= 44.09 barns/cc.

Radioactivity:

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

Kempite Classification

Dana Class:

10.01.04.01 (10)Oxyhalides and Hydroxyhalides

(10.01)where (A)2 (O,OH)3 Xq

(10.01.04)Dana Group

10.01.04.01 Kempite Mn2Cl(OH)3 Pnam 2/m 2/m 2/m

Strunz Class:

03.DA.10a 03 - HALIDES

03.D - Oxyhalides, Hydroxyhalides and Related Double Halides

03.DA -With Cu, etc., without Pb

03.DA.10a Atacamite Cu2Cl(OH)3 Pmcn 2/m 2/m 2/m

03.DA.10a Hibbingite (Fe,Mg)2(OH)3Cl Pnam 2/m 2/m 2/m

03.DA.10a Kempite Mn2Cl(OH)3 Pnam 2/m 2/m 2/m

Other Kempite 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 Kempite :
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 Kempite Specimen Label here :

Kempite

Mn2Cl(OH)3
Dana No: 10.01.04.01 Strunz No: 03.DA.10a
Locality:

Notes:

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