Ludlockite Mineral Data

General Ludlockite Information

Chemical Formula:

(Fe++,Pb)As+++++2O6

Composition:

Molecular Weight = 309.25 gm

Iron 17.16 % Fe 22.07 % FeO

Arsenic 48.45 % As 74.32 % As₂O₅

Lead 3.35 % Pb 3.61 % PbO

Oxygen 31.04 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺_0.95Pb_0.05As₂O₆

Environment:

Oxidized ore bodies containing lead, iron, and As bearing sulfosalts. Found with zincian siderite in the "germanite section" at Tsumeb.

IMA Status:

Approved IMA 1970

Locality:

In a boulder of ore found at Tsumeb, Namibia. Link to MinDat.org Location Data.

Name Origin:

Named for F. Ludlow Smith III and C. Locke Key, mineral collectors and dealers in New Jersy.

Name Pronunciation:

Ludlockite + Pronunciation

Synonym:

ICSD 82486

Ludlockite-Pb

PDF 29-774

Ludlockite Image

Images:

Ludlockite

Comments: Acicular crystals of red-orange ludlockite on quartz and chalcocite.
Location: Tsumeb Mine, Tsumeb, Namibia. Scale: Crystal size 0.4 cm.
© John Veevaert

Ludlockite Crystallography

Axial Ratios:

a:b:c =0.846:1:0.8251

Cell Dimensions:

a = 10.11, b = 11.95, c = 9.86, Z = 9; alpha = 113.9°, beta = 99.7°, gamma = 82.74° V = 1,064.91 Den(Calc)= 4.34

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: A1

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

By Intensity(I/I_o): 8.81(1), 2.94(0.9), 2.86(0.7),3.16(0.7), 3.33(0.7), 4.47(0.6), 4.74(0.6), 10.9(0.6), 3.33(0.4),

Physical Properties of Ludlockite

Cleavage:

{011} Good, {???} Good

Color:

Copper red.

Density:

4.35 - 4.4, Average = 4.37

Fracture:

Sectile - Curved shavings or scrapings produced by a knife blade, (e.g. graphite).

Habit:

Acicular - Occurs as needle-like crystals.

Hardness:

1.5-2 - Talc-Gypsum

Luster:

Subadamantine

Streak:

light brown

Optical Properties of Ludlockite

Gladstone-Dale:

CI meas= -0.428 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.45 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2417,KPDmeas= 0.2381,KC= 0.1667
Ncalc = 1.72 - 1.73

Optical Data:

Biaxial (+), a=1.96, b=2.055, g=2.11, bire=0.1500

Pleochroism (x):

yellow.

Pleochroism (y):

deep yellow.

Pleochroism (z):

orange yellow.

Calculated Properties of Ludlockite

Electron Density:

Bulk Density (Electron Density)=4.04 gm/cc
note: Specific Gravity of Ludlockite =4.38 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Ludlockite= 95.04 barns/electron
U=PE_Ludlockite x rElectron Density= 383.99 barns/cc.

Radioactivity:

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

Ludlockite Classification

Dana Class:

38.05.04.01 (38)Anhydrous Phosphates, etc

(38.05)with miscellaneous formulae

(38.05.04)Dana Group

38.05.04.01 Ludlockite (Fe,Pb)As2O6 A1 1

Strunz Class:

04.JA.45 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.J - Arsenites, Antimonites, Bismuthites, Sulfites,

04.JA -Arsenites, antimonites, bismuthites; without additional anions, without H2O

04.JA.45 Ludlockite (Fe,Pb)As2O6 A1 1

04.JA.45 Ludlockite-(Pb)* PbFe4As10O22 P1 1

Other Ludlockite Information

References:

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

See Also:

Links to other databases for Ludlockite :
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 - HyperPhysics
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

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

Ludlockite

(Fe++,Pb)As+++++2O6
Dana No: 38.05.04.01 Strunz No: 04.JA.45
Locality:

Notes:

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