Apjohnite Mineral Data

Apjohnite Mineral Data +

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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)

IMA Status:

Valid Species (Pre-IMA) 1838

Locality:

Link to MinDat.org Location Data.

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 - PrismaticH-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),

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
P - Polyhedra On/Off
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Menchetti S , Sabelli C , Mineralogical Magazine , 40 (1976) p.599-608, The halotrichite group: The crystal structure of apjohnite, Locality: Terlano, Bolzano, Italy

Physical Properties of Apjohnite

Color:

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

Density:

1.8

Diaphaniety:

Transparent

Habit:

Encrustations - Forms crust-like aggregates on matrix.

Habit:

Fibrous - Crystals made up of fibers.

Hardness:

1.5-2 - Talc-Gypsum

Luminescence:

None.

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

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:

r_electron=1.95 gm/cc
note: r_Apjohnite=1.87 gm/cc.

Fermion Index

Fermion Index = 0.00141
Boson Index = 0.99859

Photoelectric:

PE_Apjohnite= 2.64 barns/electron
U=PE_Apjohnite x r_electron= 5.14 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Apjohnite is Not Radioactive

Apjohnite Classification

Dana Class:

29.7.3.3 (29)Hydrated Acid and Sulfates

(29.7)where A (B)2 (XO4)4 · x(H2O)

(29.7.3)Halotrichite Group (Monoclinic with 22 H2O)

29.7.3.1 Pickeringite MgAl2(SO4)4·22(H2O) P 2 2

29.7.3.2 Halotrichite FeAl2(SO4)4·22(H2O) P 2 2

29.7.3.3 Apjohnite MnAl2(SO4)4·22(H2O) P 2₁/c 2/m

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

29.7.3.5 Bilinite FeFe2(SO4)4·22(H2O) P 2₁/c 2/m

29.7.3.6 Redingtonite (Fe,Mg,Ni)(Cr,Al)2(SO4)4·22(H2O) Mono

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

Strunz Class:

VI/C.12-30 VI - Sulfates,Chromates,Molybdates and Tungstates

VI/C - Water-bearing sulfates without unfamiliar anions. cations of medium and very big size

VI/C.12 - Halotrichite group, Pickeringite - Bilinite

VI/C.12-10 Pickeringite MgAl2(SO4)4·22(H2O) P 2 2

VI/C.12-12 Wupatkiite (Co,Mg,Ni)Al2(SO4)4·22(H2O) P 2₁/c 2/m

VI/C.12-20 Halotrichite FeAl2(SO4)4·22(H2O) P 2 2

VI/C.12-30 Apjohnite MnAl2(SO4)4·22(H2O) P 2₁/c 2/m

VI/C.12-40 Dietrichite (Zn,Fe,Mn)Al2(SO4)4·22(H2O) P 2₁/c 2/m

VI/C.12-50 Redingtonite (Fe,Mg,Ni)(Cr,Al)2(SO4)4·22(H2O) Mono

VI/C.12-60 Bilinite FeFe2(SO4)4·22(H2O) P 2₁/c 2/m

Other Apjohnite Information

References:

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

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

Apjohnite

MnAl2(SO4)4·22(H2O)
Dana No: 29.7.3.3 Strunz No: VI/C.12-30
Locality:

Notes: