Woodruffite Mineral Data

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.

Name Pronunciation:

Woodruffite + Pronunciation

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:

Tetragonal Space 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),

Physical Properties of Woodruffite

Cleavage:

None

Color:

Brown, Iron black, Black brown.

Density:

4.01

Diaphaneity:

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= 2.12 - from Gladstone-Dale relationship (KC = 0.3315) where Ncalc=Dcalc*KC+1
NCalc= 2.33 - from Gladstone-Dale relationship (KC = 0.3315) where Ncalc=Dmeas*KC+1

Calculated Properties of Woodruffite

Electron Density:

Bulk Density (Electron Density)=3.23 gm/cc
note: Specific Gravity of Woodruffite =3.37 gm/cc.

Fermion Index:

Fermion Index = 0.0078057293
Boson Index = 0.9921942707

Photoelectric:

PE_Woodruffite= 20.14 barns/electron
U=PE_Woodruffite x rElectron Density= 65.07 barns/cc.

Radioactivity:

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

Woodruffite Classification

Dana Class:

07.08.01.02 (07)Multiple Oxides

(07.08)where A B (O)2ï¿½x(H2O)

(07.08.01)Dana Group

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

07.08.01.02 Woodruffite (Zn,Mn)2Mn5O12•4(H2O) Unk Tetra

Strunz Class:

04.FL.25 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.F - Hydroxides (without V or U)

04.FL -Hydroxides with H2O ï¿½ (OH); sheets of edge-sharing octahedra

04.FL.25 Woodruffite (Zn,Mn)2Mn5O12•4(H2O) Unk Tetra

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 - Ecole des Mines de Paris
5 - Franklin Minerals(Dunn)
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

Search for Woodruffite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Woodruffite :

Ask about Woodruffite 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 Woodruffite Specimen Label here :

Woodruffite

(Zn,Mn++)2Mn++++5O12•4(H2O)
Dana No: 07.08.01.02 Strunz No: 04.FL.25
Locality:

Notes:

Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.