Molybdophyllite Mineral Data

General Molybdophyllite Information

Chemical Formula:

Pb9Mg9Si9O24(OH)24

Composition:

Molecular Weight = 3,128.48 gm

Magnesium 6.99 % Mg 11.59 % MgO

Silicon 8.08 % Si 17.29 % SiO₂

Hydrogen 0.77 % H 6.91 % H₂O

Lead 59.61 % Pb 64.21 % PbO

Oxygen 24.55 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Pb₉Mg₉Si₉O₂₄(OH)₂₄

IMA Status:

Valid Species (Pre-IMA) 1901

Locality:

Langbanshyttan, Vermland. Sweden. Link to MinDat.org Location Data.

Name Origin:

Named from the Greek for "lead" and "leaf", in allusion to its composition and foliated habit.

Name Pronunciation:

Molybdophyllite + Pronunciation

Molybdophyllite Crystallography

Axial Ratios:

a:c = 1:2.92818

Cell Dimensions:

a = 9.371, c = 27.44, Z = 2; V = 2,086.83 Den(Calc)= 4.98

Crystal System:

Hexagonal - Trapezohedral H-M Symbol (6 2 2) Space Group: P 6₃22

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

By Intensity(I/I_o): 13.8(1), 4.6(0.9), 2.67(0.7),

Physical Properties of Molybdophyllite

Cleavage:

{0001} Perfect

Color:

Colorless, Pale green, Pale yellow.

Density:

4.7

Diaphaneity:

Transparent to translucent

Habit:

Massive - Lamellar - Distinctly foliated fine-grained forms.

Hardness:

3-4 - Calcite-Fluorite

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Molybdophyllite

Gladstone-Dale:

CI meas= 0.002 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.058 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1582,KPDmeas= 0.1677,KC= 0.168
Ncalc = 1.79 - 1.84

Optical Data:

Uniaxial (-), e=1.761, w=1.815, bire=0.0540.

Calculated Properties of Molybdophyllite

Electron Density:

Bulk Density (Electron Density)=4.15 gm/cc
note: Specific Gravity of Molybdophyllite =4.70 gm/cc.

Fermion Index:

Fermion Index = 0.14
Boson Index = 0.86

Photoelectric:

PE_{Molybdophyllite}=1,037.74 barns/electron
U=PE_{Molybdophyllite} x rElectron Density=4,302.92 barns/cc.

Radioactivity:

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

Molybdophyllite Classification

Dana Class:

78.05.07.01 (78)Unclassified silicates

(78.05)possible phyllosilicates

(78.05.07)Dana Group

78.05.07.01 Molybdophyllite Pb9Mg9Si9O24(OH)24 P 6₃22 6 2 2

Strunz Class:

09.HH.25 09 - SILICATES (Germanates)

09.H - Unclassified Silicates

09.HH -With Pb

09.HH.25 Molybdophyllite Pb9Mg9Si9O24(OH)24 P 6₃22 6 2 2

Other Molybdophyllite Information

References:

NAME( Ford32) PHYS. PROP.(Dana8) OPTIC PROP.(Ford32)

See Also:

Links to other databases for Molybdophyllite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (MinSocAm)
8 - Handbook of Mineralogy (UofA)
9 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info

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Molybdophyllite

Pb9Mg9Si9O24(OH)24
Dana No: 78.05.07.01 Strunz No: 09.HH.25
Locality:

Notes:

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