Starkeyite Mineral Data

General Starkeyite Information

Chemical Formula:

MgSO4•4(H2O)

Composition:

Molecular Weight = 192.43 gm

Magnesium 12.63 % Mg 20.94 % MgO

Hydrogen 4.19 % H 37.45 % H₂O

Sulfur 16.66 % S 41.61 % SO₃

Oxygen 66.52 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg(SO₄)•4(H₂O)

Environment:

Secondary mineral formed in the presence of iron sulfides; as efflorescences from evaporation of surface and ground waters.

IMA Status:

Valid Species (Pre-IMA) 1956

Locality:

Starkey mine, Madison Co., Missouri, USA. Link to MinDat.org Location Data.

Name Origin:

Named for the localtiy.

Name Pronunciation:

Starkeyite + Pronunciation

Synonym:

ICSD 23911

PDF 24-720

Starkeyite Image

Images:

Starkeyite

Comments: Translucent starkeyite on rock.
Location: Barvue Mine, Barville, Quebec, Canada. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Starkeyite Crystallography

Axial Ratios:

a:b:c =0.4353:1:0.581

Cell Dimensions:

a = 5.922, b = 13.604, c = 7.905, Z = 4; beta = 90.85° V = 636.78 Den(Calc)= 2.01

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/n

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

By Intensity(I/I_o): 2.95(1), 4.48(1), 5.5(0.6),

Crystal Structure:

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drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
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S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
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Baur W H , Acta Crystallographica , 15 (1962) p.815-826, Zur kristallchemie der salzhydrate. Die kristallstrukturen von MgSO4*4H2O, (leonhardtit) und FeSO4*4H2O (rozenit), Locality: synthetic

View Additional jPOWD Structure files for Starkeyite
[1]

Physical Properties of Starkeyite

Color:

White.

Density:

2.007

Diaphaneity:

Transparent to Translucent

Hardness:

2-3 - Gypsum-Calcite

Luster:

Earthy (Dull)

Streak:

white

Optical Properties of Starkeyite

Gladstone-Dale:

CI meas= -0.011 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.009 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2451,KPDmeas= 0.2455,KC= 0.2429
Ncalc = 1.49

Optical Data:

Biaxial (+), a=1.49, b=1.491, g=1.497, bire=0.0070, 2V(Calc)=46, 2V(Meas)=50.

Calculated Properties of Starkeyite

Electron Density:

Bulk Density (Electron Density)=2.09 gm/cc
note: Specific Gravity of Starkeyite =2.01 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Starkeyite= 1.38 barns/electron
U=PE_Starkeyite x rElectron Density= 2.88 barns/cc.

Radioactivity:

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

Starkeyite Classification

Dana Class:

29.06.06.02 (29)Hydrated Acid and Sulfates

(29.06)where A XO4 · x(H2O)

(29.06.06)Rozenite Group (Monoclinic)

29.06.06.01 Rozenite FeSO4•4(H2O) P 2₁/n 2/m

29.06.06.02 Starkeyite MgSO4•4(H2O) P 2₁/n 2/m

29.06.06.03 Ilesite (Mn,Zn,Fe)SO4•4(H2O) P 2₁/n 2/m

29.06.06.04 Aplowite (Co,Mn,Ni)SO4•4(H2O) P 2₁/m 2/m

29.06.06.05 Boyleite (Zn,Mg)SO4•4(H2O) P 2₁/n 2/m

29.06.06.06 IMA2002-034! CdSO4•4(H2O) P 2₁/n 2/m

Strunz Class:

07.CB.15 07 - SULFATES (SELENATES, TELLURATES)

07.C - Sulfates (selenates, etc.) without Additional Anions, with H2O

07.CB -With only medium-sized cations

07.CB.15 Boyleite (Zn,Mg)SO4•4(H2O) P 2₁/n 2/m

07.CB.15 Aplowite (Co,Mn,Ni)SO4•4(H2O) P 2₁/m 2/m

07.CB.15 Ilesite (Mn,Zn,Fe)SO4•4(H2O) P 2₁/n 2/m

07.CB.15 Rozenite FeSO4•4(H2O) P 2₁/n 2/m

07.CB.15 Starkeyite MgSO4•4(H2O) P 2₁/n 2/m

07.CB.15 IMA2002-034! CdSO4•4(H2O) P 2₁/n 2/m

Other Starkeyite Information

References:

NAME( AntBidBlaNic5) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Starkeyite :
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 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

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

Starkeyite

MgSO4•4(H2O)
Dana No: 29.06.06.02 Strunz No: 07.CB.15
Locality:

Notes: