Weilite Mineral Data

General Weilite Information

Chemical Formula:

CaHAsO4

Composition:

Molecular Weight = 180.01 gm

Calcium 22.26 % Ca 31.15 % CaO

Arsenic 41.62 % As 63.84 % As₂O₅

Hydrogen 0.56 % H 5.00 % H₂O

Oxygen 35.55 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

CaH(AsO₄)

Environment:

Secondary mineral in oxidized As-rich veins, usually an alteration product of pharmacolite and haidingerite.

IMA Status:

Approved IMA 1963

Locality:

Schneeberg, Saxony, Germany. Link to MinDat.org Location Data.

Name Origin:

Named for Rene Weil (1901-), mineralogist of Strasbourg, France, known for his study of Alsatian minerals.

Name Pronunciation:

Weilite

Synonym:

ICSD 16039

PDF 16-701

Weilite Image

Images:

Weilite

Comments: White, radial aggregates weilite on matrix.
Location: Schlema, Schlema-Hartenstein area, Erzgebirge, Saxony, Germany. Scale: Picture size 4 mm.
© Thomas Witzke / Abraxas-Verlag

Weilite Crystallography

Axial Ratios:

a:b:c =1.0244:1:1.0302

Cell Dimensions:

a = 7.11, b = 6.94, c = 7.15, Z = 4; alpha = 94.32°, beta = 101.6°, gamma = 87.37° V = 344.25 Den(Calc)= 3.47

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 3.05(1), 3.43(1), 2.79(0.7),

Physical Properties of Weilite

Cleavage:

None

Color:

White.

Density:

3.48

Diaphaneity:

Porcelanous

Habit:

Encrustations - Forms crust-like aggregates on matrix.

Habit:

Powdery - Forms a loose, poorly-coherent pulverulent mass.

Luster:

Greasy (Oily)

Streak:

white

Optical Properties of Weilite

Gladstone-Dale:

CI meas= -0.032 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.035 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1923,KPDmeas= 0.1918,KC= 0.1859
Ncalc = 1.64 - 1.65

Optical Data:

Biaxial (-), a=1.644, b=1.67, g=1.688, bire=0.0440, 2V(Calc)=78, 2V(Meas)=82.

Calculated Properties of Weilite

Electron Density:

Bulk Density (Electron Density)=3.33 gm/cc
note: Specific Gravity of Weilite =3.48 gm/cc.

Fermion Index:

Fermion Index = 0.0004720717
Boson Index = 0.9995279283

Photoelectric:

PE_Weilite= 31.07 barns/electron
U=PE_Weilite x rElectron Density= 103.30 barns/cc.

Radioactivity:

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

Weilite Classification

Dana Class:

37.01.01.02 (37)Anhydrous Acid Phosphates, etc

(37.01)with miscellaneous formulae

(37.01.01)Dana Group

37.01.01.01 Monetite CaHPO4 P1 1

37.01.01.02 Weilite CaHAsO4 P1 1

Strunz Class:

08.AD.10 08 - PHOSPHATES, ARSENATES, VANADATES

08.A - Phosphates, etc. without additional anions, without H2O

08.AD -With only large cations

08.AD.10 Monetite CaHPO4 P1 1

08.AD.10 Weilite CaHAsO4 P1 1

08.AD.10 Svenekite! Ca(H2AsO4)2 P1 1

Other Weilite Information

References:

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

See Also:

Links to other databases for Weilite :
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

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

Weilite

CaHAsO4
Dana No: 37.01.01.02 Strunz No: 08.AD.10
Locality:

Notes:

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