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Mereheadite Mineral Data

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General Mereheadite Information

Help on Chemical  Formula: Chemical Formula: Pb2O(OH)Cl
Help on Composition: Composition: Molecular Weight = 482.86 gm
   Hydrogen   0.21 %  H     1.87 % H2O
   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
Help on Empirical Formula: Empirical Formula: Pb2O(OH)Cl
Help on Environment: Environment: In lenses and cavities in veins of manganese and iron minerals which cut dolomitic limestones. Related to litharge.
Help on IMA Status: IMA Status: Approved IMA 1998 (Dana # Added)
Help on Locality: Locality: Merehead Quarry, Cranmore, Somerset, England, U.K. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after its locality.
Help on Name Pronunciation: Name Pronunciation: Mereheadite + Pronunciation Say MEREHEADITE
Help on Synonym: Synonym: IMA1996-045

Mereheadite Image

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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

Help on Axial Ratios: Axial Ratios: a:b:c =1.0206:1:2.3617
Help on Cell Dimensions: Cell Dimensions: a = 5.68, b = 5.565, c = 13.143, Z = 4; beta = 90.64° V = 415.41 Den(Calc)= 7.72
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.93(1), 3.785(0.5), 2.825(0.4),

Physical Properties of Mereheadite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: Pale yellow, Reddish orange.
Help on Density: Density: 7.12 - 7.69, Average = 7.4
Help on Diaphaneity: Diaphaneity: Translucent
Help on Fracture: Fracture: Conchoidal - Uneven - Uneven fracture producing small, conchoidal fragments.
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Hardness: Hardness: 3.5 - Copper Penny
Help on Luster: Luster: Vitreous - Resinous
Help on Streak: Streak: white

Optical Properties of Mereheadite

Help on Gladstone-Dale: 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
Help on Optical Data: Optical Data: Biaxial (?), a=2.19, g=2.28, bire=0.0900

Calculated Properties of Mereheadite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=6.33 gm/cc
note: Specific Gravity of Mereheadite =7.72 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.18
Boson Index = 0.82
Help on Photoelectric: Photoelectric: PEMereheadite =1,606.99 barns/electron
U=PEMereheadite x rElectron Density=10174.34 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Mereheadite is Not Radioactive

Mereheadite Classification

Help on  Dana Class: Dana Class: (10)Oxyhalides and Hydroxyhalides
  (10.04)where (A)2 (O,OH) Xq
  (10.04.05)Dana Group Mereheadite! Pb2O(OH)Cl C 2/c 2/m
Help on  Strunz Class: 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

Help on References: References: NAME( MinRec) PHYS. PROP.(Min.Mag.,Vol.63,p387-393,1998) OPTIC PROP.(Min.Mag.,Vol.63,p387-393,1998)
Help on See Also: 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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Dana No: Strunz No: 03.DC.45





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