Mattheddleite Mineral Data

General Mattheddleite Information

Chemical Formula:

Pb20(SiO4)7(SO4)4Cl4

Composition:

Molecular Weight = 5,314.65 gm

Silicon 3.70 % Si 7.91 % SiO₂

Lead 77.97 % Pb 83.99 % PbO

Sulfur 2.41 % S 6.03 % SO₃

Chlorine 2.67 % Cl 2.67 % Cl

- % Cl -0.60 % -O=Cl₂

Oxygen 13.25 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Pb₂₀(SiO₄)₇(SO₄)₄Cl₄

Environment:

Lining cavities in quartz which contain other oxidized lead minerals.

IMA Status:

Approved IMA 1987

Locality:

From Leadhills, Lanarkshire, Scotland. Link to MinDat.org Location Data.

Name Origin:

Named for Matthew Forster Heddle (1828-1897), Scottish mineralogist.

Name Pronunciation:

Mattheddleite + Pronunciation

Mattheddleite Image

Images:

Mattheddleite

Comments: Radial aggregates of colorless hexagonal microcrystals of mattheddleite with minor blue-green caledonite.
Location: Dry Smale Gill, Roughton Gill, Caldbeck Fells, Cumbria (Cumberland), England, United Kingdom. Scale: See Image.
© Rruff Database

Mattheddleite Crystallography

Axial Ratios:

a:c = 1:0.74917

Cell Dimensions:

a = 9.963, c = 7.464, Z = 0.5; V = 641.63 Den(Calc)= 6.88

Crystal System:

Hexagonal - Dipyramidal H-M Symbol (6/m) Space Group: P 6₃/m

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

By Intensity(I/I_o): 2.988(1), 4.13(0.4), 4.32(0.4),

Physical Properties of Mattheddleite

Cleavage:

{0001} Indistinct

Color:

Colorless, White.

Diaphaneity:

Transparent to Translucent

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Habit:

Rosette - Bundled tabular aggregates resembling rose flower petals.

Hardness:

3.5-4.5 - Between Copper Penny and Fluorite-Apatite

Luminescence:

Fluorescent, Short UV=dull yellow.

Luster:

Adamantine

Streak:

white

Optical Properties of Mattheddleite

Gladstone-Dale:

CI calc= 0.005 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1465,KC= 0.1473
Ncalc = 2.01

Optical Data:

Uniaxial (-), e=1.999, w=2.017, bire=0.0180.

Calculated Properties of Mattheddleite

Electron Density:

Bulk Density (Electron Density)=5.75 gm/cc
note: Specific Gravity of Mattheddleite =6.88 gm/cc.

Fermion Index:

Fermion Index = 0.17
Boson Index = 0.83

Photoelectric:

PE_{Mattheddleite}=1,432.01 barns/electron
U=PE_{Mattheddleite} x rElectron Density=8,238.22 barns/cc.

Radioactivity:

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

Mattheddleite Classification

Dana Class:

52.04.09.06 (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O

(52.04)with cations in [6] and/or > [6] coordination

(52.04.09)Silicate apatites

52.04.09.00 Ellestadite* Ca5(SiO4,PO4,SO4)3(F,OH,Cl) P 6₃/m 6/m

52.04.09.01 Britholite-(Ce) (Ce,Ca,Th,La,Nd)5(SiO4,PO4)3(OH,F) P 6₃/m 6/m

52.04.09.02 Britholite-(Y) (Y,Ca)5(SiO4,PO4)3(OH,F) P 6₃/m 6/m

52.04.09.03 Ellestadite-(F) Ca5(SiO4,PO4,SO4)3(F,OH,Cl) P 6₃/m 6/m

52.04.09.04 Ellestadite-(OH) Ca5(SiO4,SO4)3(OH,Cl,F) P 6₃/m 6/m

52.04.09.05 Ellestadite-(Cl) Ca5(SiO4,PO4,SO4)3(Cl,OH,F) P 6₃/m 6/m

52.04.09.06 Mattheddleite Pb20(SiO4)7(SO4)4Cl4 P 6₃/m 6/m

52.04.09.07 Karnasurtite-(Ce) (Ce,La,Th)(Ti,Nb)(Al,Fe)(Si,P)2O7(OH)4•3(H2O)(?) Unk. Hex

52.04.09.08 Fluorbritholite-(Ce) (Ca,Ce,La,Na)5(SiO4,PO4)3(OH,F) P 6₃/m 6/m

52.04.09.09 Fluorcalciobritholite! (Ca,REE)5[(Si,P)O4]3F P 6₃/m 6/m

Strunz Class:

09.AH.30 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AH -Nesosilicates with CO3, SO4, PO4, etc.

09.AH.30 Mattheddleite Pb20(SiO4)7(SO4)4Cl4 P 6₃/m 6/m

09.AH.30 Tritomite-(Ce) (Ce,La,Ca,Y,Th)5(Si,B)3(O,OH,F)13 P 6₃/m 6/m

09.AH.30 Tritomite-(Y) (Y,Ca,La,Fe)5(Si,B,Al)3(O,OH,F)13(?) P 6₃/m 6/m

Other Mattheddleite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Am.Min.,Vol.73,p929,1988) OPTIC PROP.(Am.Min.,Vol.73,p929,1988)

See Also:

Links to other databases for Mattheddleite :
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

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Mattheddleite

Pb20(SiO4)7(SO4)4Cl4
Dana No: 52.04.09.06 Strunz No: 09.AH.30
Locality:

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