Mackinawite Mineral Data

General Mackinawite Information

Chemical Formula:

(Fe,Ni)S0.9

Composition:

Molecular Weight = 85.42 gm

Iron 49.04 % Fe

Nickel 17.18 % Ni

Sulfur 33.79 % S

______

100.00 %

Empirical Formula:

Fe²⁺_0.75Ni_0.25S_0.9

Environment:

Serpentinization of ultrabasic rocks.

IMA Status:

Approved IMA 1962

Locality:

Mackinaw mine, Snohomish County, Washington, USA. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Mackinawite + Pronunciation

Synonym:

ICSD 81087

PDF 24-73

Mackinawite Image

Images:

Mackinawite

Comments: Mackinawite inclusions in sulfide ore (polished specimen).
Location: Mackinaw Mine, Snohomish County, Washington, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Mackinawite Crystallography

Axial Ratios:

a:c = 1:1.36887

Cell Dimensions:

a = 3.676, c = 5.032, Z = 2; V = 68.00 Den(Calc)= 4.17

Crystal System:

Tetragonal - Ditetragonal DipyramidalH-M Symbol (4/m 2/m 2/m) Space Group: P 4/nmm

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

By Intensity(I/I_o): 5.03(1), 2.31(0.8), 2.97(0.8),

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

Lennie A R , Redfern S A T , Schofield P F , Vaughan D J , Mineralogical Magazine , 59 (1995) p.677-683, Synthesis and Rietveld crystal structure refinement of mackinawite, tetragonal, FeS, Locality: synthetic

Physical Properties of Mackinawite

Cleavage:

{001} Perfect

Color:

Bronze, White gray.

Diaphaneity:

Opaque

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Hardness:

2.5 - Finger Nail

Luster:

Metallic

Streak:

black

Optical Properties of Mackinawite

RL Anisotrophism:

Extreme.

RL Pleochroism:

Strong.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Mackinawite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
400 nm	21.00	35.50
420 nm	21.00	37.20
440 nm	21.00	38.90
460 nm	21.00	40.40
480 nm	21.10	41.80
500 nm	21.20	43.10
520 nm	21.30	44.30
540 nm	21.60	45.30
560 nm	21.90	46.10
580 nm	22.20	46.90
600 nm	22.60	47.40
620 nm	22.90	47.80
640 nm	23.30	48.20
660 nm	23.80	48.50
680 nm	24.30	48.80
700 nm	24.90	49.10

**Calculated Relative Intensity Colors of Mackinawite in Air**
Relative Intensity	0%	50%	100%	150%	200%	250%	300%	350%	400%	420%
R₁
R₂

Calculated Properties of Mackinawite

Electron Density:

Bulk Density (Electron Density)=3.99 gm/cc
note: Specific Gravity of Mackinawite =4.17 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Mackinawite= 23.63 barns/electron
U=PE_Mackinawite x rElectron Density= 94.38 barns/cc.

Radioactivity:

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

Mackinawite Classification

Dana Class:

02.07.02.01 (02)Sulfides - Including Selenides and Tellurides

(02.07)where Am Bn Xp, with (m+n):p=9:8

(02.07.02)Dana Group

02.07.02.01 Mackinawite (Fe,Ni)S0.9 P 4/nmm 4/m 2/m 2/m

02.07.02.02 Sugakiite! Cu(Fe,Ni)8S8 P 4₁/mnm 4/m 2/m 2/m

Strunz Class:

02.CC.25 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf

02.C - Metal Sulfides, M:S = 1:1 (and similar)

02.CC -With Ni, Fe, Co, PGE, etc.

02.CC.25 Mackinawite (Fe,Ni)S0.9 P 4/nmm 4/m 2/m 2/m

Other Mackinawite Information

References:

PHYS. PROP.(Dana8) OPTIC PROP.(AntBidBlaNic1)

See Also:

Links to other databases for Mackinawite :
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

Search for Mackinawite using:

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

Visit our Advertisers for Mackinawite :

A Bijoux Google Search for Mackinawite
Adam's Minerals Google Search for Mackinawite
Cape Minerals Google Search for Mackinawite
Dakota Matrix Minerals Google Search for Mackinawite
Excalibur Mineral Corp. Google Search for Mackinawite
Exceptional Minerals Google Search for Mackinawite
John Betts Fine Minerals Search for Mackinawite
McDougall Minerals Google Search for Mackinawite
Mineral News Website Link
Rock and Mineral Shows Google Search for Mackinawite
Weinrich Minerals, Inc. Google Search for Mackinawite

Ask about Mackinawite 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 Mackinawite Specimen Label here :

Mackinawite

(Fe,Ni)S0.9
Dana No: 02.07.02.01 Strunz No: 02.CC.25
Locality:

Notes: