Woodruffite Mineral Data

Woodruffite Mineral Data +

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General Woodruffite Information

Chemical Formula:

(Zn,Mn++)2Mn++++5O12·4(H2O)

Composition:

Molecular Weight = 668.48 gm

Manganese 41.91 % Mn 1.06 % MnO / 65.03 % MnO₂

Zinc 18.59 % Zn 23.13 % ZnO

Hydrogen 1.21 % H 10.78 % H₂O

Oxygen 38.29 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Zn_1.9Mn²⁺_0.1Mn⁴⁺₅O₁₂·4(H₂O)

Environment:

Oxidized material derived from the orebody outcrop.

IMA Status:

Valid Species (Pre-IMA) 1953

Locality:

Sterling Hill mine, Ogdensburg, Sussex County, New Jersey, USA. Link to MinDat.org Location Data.

Name Origin:

Named for Samuel Woodruff, late-nineteenth-century miner and mineral collector at Franklin, who collected and preserved many of the finest specimens found at that locality.

Woodruffite Image

Images:

Woodruffite

Comments: Dull brown massive woodruffite with limonite.
Location: Sterling Mine, Ogdensburg, Sussex County, New Jersey, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Woodruffite Crystallography

Axial Ratios:

a:c = 1:1.10213

Cell Dimensions:

a = 8.42, c = 9.28, Z = 2; V = 657.92 Den(Calc)= 3.37

Crystal System:

TetragonalSpace Group: Unk

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

By Intensity(I/I_o): 4.66(1), 2.48(0.6), 2.66(0.6),

Crystal Structure:

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Post J E , Heaney P J , Cahill C L , Finger L W , American Mineralogist , 88 (2003) p.1697-1702, Woodruffite: A new Mn oxide structure with 3x4 tunnels, Sample: at T = 100 K

Physical Properties of Woodruffite

Cleavage:

None

Color:

Brown, Iron black, Black brown.

Density:

4.01

Diaphaniety:

Opaque

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Botryoidal - "Grape-like" rounded forms (e.g.. malachite).

Habit:

Pulverulent - Forms a loose, poorly-coherent powdery mass.

Hardness:

4.5 - Between Fluorite and Apatite

Luster:

Earthy (Dull)

Streak:

brownish

Optical Properties of Woodruffite

Optical Data:

NCalc= 2.11 - from Gladstone-Dale relationship (KC = 0.3294) where Ncalc=Dcalc*KC+1
NCalc= 2.32 - from Gladstone-Dale relationship (KC = 0.3294) where Ncalc=Dmeas*KC+1

Calculated Properties of Woodruffite

Electron Density:

r_electron=3.23 gm/cc
note: r_Woodruffite=3.37 gm/cc.

Fermion Index

Fermion Index = 0.0078
Boson Index = 0.9922

Photoelectric:

PE_Woodruffite= 20.14 barns/electron
U=PE_Woodruffite x r_electron= 65.07 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Woodruffite is Not Radioactive

Woodruffite Classification

Dana Class:

7.8.1.2 (7)Multiple Oxides

(7.8)where A B (O)2·x(H2O)

(7.8.1)Dana Group

7.8.1.1 Todorokite (Na,Ca,K)2(Mn,Mn)6O12·3-4.5(H2O) P 2/m 2/m

7.8.1.2 Woodruffite (Zn,Mn)2Mn5O12·4(H2O) Unk Tetra

Strunz Class:

IV/D.09-20 IV - Oxides

IV/D - Oxides with metal : oxygen = 1:2 (MO2 and related compounds)

IV/D.09 - Todorokite - Romanechite series

IV/D.09-10 Todorokite (Na,Ca,K)2(Mn,Mn)6O12·3-4.5(H2O) P 2/m 2/m

IV/D.09-20 Woodruffite (Zn,Mn)2Mn5O12·4(H2O) Unk Tetra

IV/D.09-30 Romanechite (Ba,H2O)2(Mn,Mn)5O10 C 2/m 2/m

Other Woodruffite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8)

See Also:

Links to other databases for Woodruffite :
1 -Am. Min. Crystal Structure Database 2 -Athena 3 - EUROmin Project 4 - Franklin Minerals(Dunn) 5 -Google Images 6 -Google Scholar 7 -MinDAT 8 -MinMax(Deutsch) 9 -MinMax(English) 10 -Mineralienatlas (Deutsch) 11 -QUT Mineral Atlas 12 -École des Mines de Paris

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Translate Woodruffite Mineral Data :

Ask about Woodruffite here :
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Print or Cut-and-Paste your Woodruffite Specimen Label here :

Woodruffite

(Zn,Mn++)2Mn++++5O12·4(H2O)
Dana No: 7.8.1.2 Strunz No: IV/D.09-20
Locality:

Notes: