Apjohnite Mineral Data

General Apjohnite Information

Chemical Formula:

MnAl2(SO4)4•22(H2O)

Composition:

Molecular Weight = 889.49 gm

Manganese 6.18 % Mn 7.98 % MnO

Aluminum 6.07 % Al 11.46 % Al₂O₃

Hydrogen 4.99 % H 44.56 % H₂O

Sulfur 14.42 % S 36.00 % SO₃

Oxygen 68.35 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺Al₂(SO₄)₄•22(H₂O)

Environment:

Found as efflorescences.

IMA Status:

Valid Species (Pre-IMA) 1838

Locality:

Maputo (Delagoa) Bay, near Maputo (Louren�co Marques), Mozambique. Link to MinDat.org Location Data.

Name Origin:

Named for James Apjohn (1796-1886), Professor of Chemistry and Mineralogy, Trinity College, Dublin, Ireland.

Name Pronunciation:

Apjohnite + Pronunciation

Synonym:

ICSD 14038

PDF 29-886

Apjohnite Image

Images:

Apjohnite

Comments: White crystalline mass of apjohnite.
Location: Terlano, Bolzano, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Apjohnite Crystallography

Axial Ratios:

a:b:c =0.2545:1:0.8734

Cell Dimensions:

a = 6.198, b = 24.347, c = 21.266, Z = 4; beta = 100.28° V = 3,157.58 Den(Calc)= 1.87

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/c

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

By Intensity(I/I_o): 3.52(1), 4.82(0.9), 3.79(0.35),

Physical Properties of Apjohnite

Color:

Colorless, White, Pale yellow, Pale green, Pale pink.

Density:

1.8

Diaphaneity:

Transparent

Habit:

Encrustations - Forms crust-like aggregates on matrix.

Habit:

Fibrous - Crystals made up of fibers.

Hardness:

1.5-2 - Talc-Gypsum

Luminescence:

Non-fluorescent.

Luster:

Silky

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Apjohnite

Gladstone-Dale:

CI meas= -0.049 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.009 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.257,KPDmeas= 0.267,KC= 0.2547
Ncalc = 1.46 - 1.48

Optical Data:

Biaxial (-), a=1.478, b=1.482, g=1.482, bire=0.0040, 2V(Calc)=0, 2V(Meas)=0-15. Dispersion none.

Pleochroism (x):

none.

Pleochroism (y):

none.

Pleochroism (z):

none.

Calculated Properties of Apjohnite

Electron Density:

Bulk Density (Electron Density)=1.95 gm/cc
note: Specific Gravity of Apjohnite =1.87 gm/cc.

Fermion Index:

Fermion Index = 0.0014170582
Boson Index = 0.9985829418

Photoelectric:

PE_Apjohnite= 2.64 barns/electron
U=PE_Apjohnite x rElectron Density= 5.14 barns/cc.

Radioactivity:

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

Apjohnite Classification

Dana Class:

29.07.03.03 (29)Hydrated Acid and Sulfates

(29.07)where A (B)2 (XO4)4 � x(H2O)

(29.07.03)Halotrichite Group (Monoclinic with 22 H2O)

29.07.03.01 Pickeringite MgAl2(SO4)4•22(H2O) P 2 2

29.07.03.02 Halotrichite FeAl2(SO4)4•22(H2O) P 2 2

29.07.03.03 Apjohnite MnAl2(SO4)4•22(H2O) P 2₁/c 2/m

29.07.03.04 Dietrichite (Zn,Fe,Mn)Al2(SO4)4•22(H2O) P 2₁/c 2/m

29.07.03.05 Bilinite FeFe2(SO4)4•22(H2O) P 2₁/c 2/m

29.07.03.06 Redingtonite (Fe,Mg,Ni)(Cr,Al)2(SO4)4•22(H2O) Mono

29.07.03.07 Wupatkiite (Co,Mg,Ni)Al2(SO4)4•22(H2O) P 2₁/c 2/m

Strunz Class:

07.CB.85 07 - SULFATES (SELENATES, TELLURATES)

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

07.CB -With only medium-sized cations

07.CB.85 Bilinite FeFe2(SO4)4•22(H2O) P 2₁/c 2/m

07.CB.85 Apjohnite MnAl2(SO4)4•22(H2O) P 2₁/c 2/m

07.CB.85 Dietrichite (Zn,Fe,Mn)Al2(SO4)4•22(H2O) P 2₁/c 2/m

07.CB.85 Halotrichite FeAl2(SO4)4•22(H2O) P 2 2

07.CB.85 Pickeringite MgAl2(SO4)4•22(H2O) P 2 2

07.CB.85 Redingtonite (Fe,Mg,Ni)(Cr,Al)2(SO4)4•22(H2O) Mono

07.CB.85 Wupatkiite (Co,Mg,Ni)Al2(SO4)4•22(H2O) P 2₁/c 2/m

Other Apjohnite Information

References:

NAME( AntBidBlaNic5) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)

See Also:

Links to other databases for Apjohnite :
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

Search for Apjohnite using:

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

Visit our Advertisers for Apjohnite :

Ask about Apjohnite 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 Espa�ol

Print or Cut-and-Paste your Apjohnite Specimen Label here :

Apjohnite

MnAl2(SO4)4•22(H2O)
Dana No: 29.07.03.03 Strunz No: 07.CB.85
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.