Ardennite-(As) Mineral Data

General Ardennite-(As) Information

Chemical Formula:

(Mn++,Ca,Mg)4(Al,Mg,Fe)6(SiO4)2(Si3O10)(AsO4,VO4)(OH)6

Composition:

Molecular Weight = 1,036.05 gm

Calcium 3.09 % Ca 4.33 % CaO

Magnesium 3.28 % Mg 5.45 % MgO

Manganese 14.85 % Mn 19.17 % MnO

Aluminum 12.24 % Al 23.13 % Al₂O₃

Vanadium 0.49 % V 0.88 % V₂O₅

Iron 2.16 % Fe 3.08 % Fe₂O₃

Silicon 13.55 % Si 29.00 % SiO₂

Arsenic 6.51 % As 9.98 % As₂O₅

Hydrogen 0.58 % H 5.22 % H₂O

Oxygen 43.24 % O

______ ______

100.00 % 100.23 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺_2.8Ca_0.8Mg_1.4Al_4.7Fe³⁺_0.4(AsO₄)_0.9(VO₄)_0.1(SiO₄)₂(Si₃O₁₀)(OH)₆

Environment:

In pegmatites and quartz veins in schist and highly oxidized Mn, Al-rich metasediments. Forms a series with ardennite-(V).

IMA Status:

Valid Species (Pre-IMA) 1872, Renamed 2007 to Adrennite-(As)

Locality:

Salmchateau in the Ardennes Mountains, Belgium. Link to MinDat.org Location Data.

Name Origin:

After the locality. Renamed to ardennite-(As) with the discovery of ardennite-(V).

Name Pronunciation:

Ardennite-(As) + Pronunciation

Synonym:

Ardennite

Dewalquite

Ardennite-(As) Image

Images:

Ardennite-(As)

Comments: Yellow ardennite crystals in white quartz matrix.
Location: Salmchâteau, Vielsalm, Stavelot Massif, Ardennes, Luxembourg Province, Belgium. Scale: 30x20x17 mm.
© John Betts - Fine Minerals

Ardennite-(As) Crystallography

Axial Ratios:

a:b:c =0.4698:1:0.3141

Cell Dimensions:

a = 8.72, b = 18.56, c = 5.83, Z = 2; V = 943.55 Den(Calc)= 3.65

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pnmm

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

By Intensity(I/I_o): 2.574(1), 2.911(0.7), 4.21(0.6),

Physical Properties of Ardennite-(As)

Cleavage:

{010} Perfect, {110} Distinct, {001} Parting

Color:

Yellow, Yellow brown, Dark brown, Orange, Black.

Density:

3.62 - 3.75, Average = 3.68

Diaphaneity:

Nearly opaque

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

6-7 - Orthoclase-Quartz

Luster:

Subadamantine

Streak:

pale brownish yellow

Optical Properties of Ardennite-(As)

Gladstone-Dale:

CI meas= 0.023 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.014 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2096,KPDmeas= 0.2076,KC= 0.2125
Ncalc = 1.77 - 1.8

Optical Data:

Biaxial (+), b=1.74-1.79, 2V(Meas)=0-70. Dispersion strong, r > v.

Pleochroism (x):

dark brownish yellow.

Pleochroism (y):

golden yellow.

Pleochroism (z):

pale yellow.

Calculated Properties of Ardennite-(As)

Electron Density:

Bulk Density (Electron Density)=3.57 gm/cc
note: Specific Gravity of Ardennite-(As) =3.65 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Ardennite-(As)}= 10.16 barns/electron
U=PE_{Ardennite-(As)} x rElectron Density= 36.25 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Ardennite-(As) is Not Radioactive

Ardennite-(As) Classification

Dana Class:

58.03.01.01 (58)Sorosilicate Insular, Mixed, Single, and Larger Tetrahedral Groups

(58.03)with insular single and triple groups (n=1,3)

(58.03.01)Ardennite group

58.03.01.01 Ardennite-(As) (Mn,Ca,Mg)4(Al,Mg,Fe)6(SiO4)2(Si3O10)(AsO4,VO4)(OH)6 Pnmm 2/m 2/m 2/m

58.03.01.02 Orientite Ca2MnMn2Si3O10(OH)4 C mcm 2/m 2/m 2/m

58.03.01.03 Ardennite-(V)! Mn4[Al4(Mg,Al,Fe,Mn)2][Si5(V,Si)]O22(OH)6 Pnmm 2/m 2/m 2/m

Strunz Class:

09.BJ.40 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BJ -Sorosilicates with Si3O10, Si4O11, etc

09.BJ.40 Ardennite-(As) (Mn,Ca,Mg)4(Al,Mg,Fe)6(SiO4)2(Si3O10)(AsO4,VO4)(OH)6 Pnmm 2/m 2/m 2/m

09.BJ.40 Ardennite-(V)! Mn4[Al4(Mg,Al,Fe,Mn)2][Si5(V,Si)]O22(OH)6 Pnmm 2/m 2/m 2/m

Other Ardennite-(As) Information

References:

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

See Also:

Links to other databases for Ardennite-(As) :
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 Ardennite-(As) Specimen Label here :

Ardennite-(As)

(Mn++,Ca,Mg)4(Al,Mg,Fe)6(SiO4)2(Si3O10)(AsO4,VO4)(OH)6
Dana No: 58.03.01.01 Strunz No: 09.BJ.40
Locality:

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