Mereheadite Mineral Data
General Mereheadite Information
Chemical Formula:
Pb2O(OH)Cl
Composition:
Molecular Weight = 482.86 gm
Hydrogen 0.21 % H 1.87 % H2 O
Lead 85.82 % Pb 92.45 % PbO
Chlorine 7.34 % Cl 7.34 % Cl
- %
Cl -1.66 % -O=Cl2
Oxygen 6.63 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Pb2 O(OH)Cl
Environment:
In lenses and cavities in veins of manganese and iron minerals which cut dolomitic limestones. Related to litharge.
IMA Status:
Approved IMA 1998 (Dana # Added)
Locality:
Merehead Quarry, Cranmore, Somerset, England, U.K. Link to MinDat.org Location Data.
Name Origin:
Named after its locality.
Name Pronunciation:
Mereheadite + Pronunciation
Synonym:
IMA1996-045
Mereheadite Image
Images:
Mereheadite
Comments: Yellowish crystals of mereheadite to 1mm embedded in matrix.
Location: Merehead quarry, Shepton Mallet, Somerset, England.
Scale: Picture size 5 mm.
© Tom Loomis / Dakota Matrix
Mereheadite Crystallography
Axial Ratios:
a:b:c =1.0206:1:2.3617
Cell Dimensions:
a = 5.68, b = 5.565, c = 13.143, Z = 4; beta = 90.64° V = 415.41 Den(Calc)= 7.72
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c
X Ray Diffraction:
By Intensity(I/Io ): 2.93(1), 3.785(0.5), 2.825(0.4),
Physical Properties of Mereheadite
Cleavage:
{001} Perfect
Color:
Pale yellow, Reddish orange.
Density:
7.12 - 7.69, Average = 7.4
Diaphaneity:
Translucent
Fracture:
Conchoidal - Uneven - Uneven fracture producing small, conchoidal fragments.
Habit:
Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Hardness:
3.5 - Copper Penny
Luster:
Vitreous - Resinous
Streak:
white
Optical Properties of Mereheadite
Gladstone-Dale:
CI meas = -0.094 (Poor) - where the CI = (1-KPDmeas /KC ) CI calc = -0.049 (Good) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.16,KPDmeas = 0.1668,KC = 0.1525 Ncalc = 2.09 - 2.18
Optical Data:
Biaxial (?), a=2.19, g=2.28, bire=0.0900
Calculated Properties of Mereheadite
Electron Density:
Bulk Density (Electron Density)=6.33 gm/cc note: Specific Gravity of Mereheadite =7.72 gm/cc.
Fermion Index:
Fermion Index = 0.18 Boson Index = 0.82
Photoelectric:
PEMereheadite =1,606.99 barns/electronU=PEMereheadite x r Electron Density=10174.34 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Mereheadite is Not Radioactive
Mereheadite Classification
Dana Class:
10.04.05.01 (10) Oxyhalides and Hydroxyhalides
(10.04) where (A)2 (O,OH) Xq
(10.04.05) Dana Group
10.04.05.01 Mereheadite ! Pb2O(OH)Cl C 2/c 2/m
Strunz Class:
03.DC.45 03 - HALIDES
03.D - Oxyhalides, Hydroxyhalides and Related Double Halides
03.DC -With Pb (As,Sb,Bi), without Cu
03.DC.45 Mereheadite ! Pb2O(OH)Cl C 2/c 2/m
Other Mereheadite Information
References:
NAME( MinRec) PHYS. PROP.(Min.Mag.,Vol.63,p387-393,1998) OPTIC PROP.(Min.Mag.,Vol.63,p387-393,1998)
See Also:
Links to other databases for Mereheadite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (MinSocAm)
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info
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Print or Cut-and-Paste your Mereheadite Specimen Label here :
Mereheadite
Pb2O(OH)Cl
Dana No: 10.04.05.01 Strunz No: 03.DC.45
Locality:
Notes:
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