Manganohornesite Mineral Data

General Manganohornesite Information

Chemical Formula:

(Mn,Mg)3(AsO4)2•8(H2O)

Composition:

Molecular Weight = 563.80 gm

Magnesium 3.23 % Mg 5.36 % MgO

Manganese 21.92 % Mn 28.31 % MnO

Arsenic 26.58 % As 40.77 % As₂O₅

Hydrogen 2.86 % H 25.56 % H₂O

Oxygen 45.40 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺_2.25Mg_0.75(AsO₄)₂•8(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1951

Locality:

Langban, varmland, Sweden. Link to MinDat.org Location Data.

Name Origin:

Named for the composition and relationship to hornesite.

Synonym:

Manganese-hornesite - Renamed as Manganohornesite by Mineralogical Record, v330 (2008), p131

Manganohornesite Image

Images:

Manganohornesite

Comments: Micro, white, needles of manganese-hornesite to about 0.75mm on hausmannite-rich matrix.
Location: Langban, Varmland, Sweden. Scale: 5.5 x 4 x 2.5cm.
© Tom Loomis / Dakota Matrix

Manganohornesite Crystallography

Axial Ratios:

a:b:c =0.3695:1:0.1699

Cell Dimensions:

a = 10.38, b = 28.09, c = 4.774, Z = 4; beta = 105.7° V = 1,340.04 Den(Calc)= 2.79

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): 7.01(1), 8.19(0.8), 3.02(0.7),

Physical Properties of Manganohornesite

Color:

White.

Density:

2.64

Diaphaneity:

Transparent to Translucent

Habit:

Stellate - Occurs as spherical, radial aggregates radiating from a "star" like point.

Hardness:

1 - Talc

Optical Properties of Manganohornesite

Gladstone-Dale:

CI meas= -0.022 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.033 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2123,KPDmeas= 0.2244,KC= 0.2194
Ncalc = 1.58 - 1.61

Optical Data:

Biaxial (+), a=1.579, b=1.589, g=1.609, bire=0.0300, 2V(Calc)=72, 2V(Meas)=65-70.

Calculated Properties of Manganohornesite

Electron Density:

Bulk Density (Electron Density)=2.58 gm/cc
note: Specific Gravity of Manganohornesite =2.64 gm/cc.

Fermion Index:

Fermion Index = 0.0034554265
Boson Index = 0.9965445735

Photoelectric:

PE_{Manganohornesite}= 23.33 barns/electron
U=PE_{Manganohornesite} x rElectron Density= 60.14 barns/cc.

Radioactivity:

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

Manganohornesite Classification

Dana Class:

40.03.07.02 (40)Hydrated Phosphates, etc

(40.03)where (A++)3 (XO4)2 � x(H2O)

(40.03.07)Dana Group

40.03.07.01 Bobierrite Mg3(PO4)2•8(H2O) C 2/c 2/m

40.03.07.02 Manganohornesite (Mn,Mg)3(AsO4)2•8(H2O) P 2₁/c 2/m

Strunz Class:

08.CE.40 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CE -With only medium-sized cations, RO4:H2O � 1:2.5

08.CE.40 Arupite (Ni,Fe)3(PO4)2•8(H2O) I2/m 2/m

08.CE.40 Annabergite Ni3(AsO4)2•8(H2O) I2/m 2/m

08.CE.40 Baricite (Mg,Fe)3(PO4)2•8(H2O) C 2/m 2/m

08.CE.40 Erythrite Co3(AsO4)2•8(H2O) I2/m 2/m

08.CE.40 Ferrisymplesite Fe3(AsO4)2(OH)3•5(H2O) None

08.CE.40 Hornesite Mg3(AsO4)2•8(H2O) I2/m 2/m

08.CE.40 Kottigite Zn3(AsO4)2•8(H2O) C 2/m 2/m

08.CE.40 Manganohornesite (Mn,Mg)3(AsO4)2•8(H2O) P 2₁/c 2/m

08.CE.40 Parasymplesite Fe3(AsO4)2•8(H2O) C 2/m 2/m

08.CE.40 Vivianite Fe3(PO4)2•8(H2O) C 2/m 2/m

08.CE.40 Pakhomovskyite! Co3(PO4)2•8(H2O) C 2/m 2/m

Other Manganohornesite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Manganohornesite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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

Manganohornesite

(Mn,Mg)3(AsO4)2•8(H2O)
Dana No: 40.03.07.02 Strunz No: 08.CE.40
Locality:

Notes:

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