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Barstowite Mineral Data

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General Barstowite Information

Help on Chemical  Formula: Chemical Formula: Pb4(CO3)Cl6•(H2O)
Help on Composition: Composition: Molecular Weight = 1,119.54 gm
   Hydrogen   0.18 %  H     1.61 % H2O
   Lead      74.03 %  Pb   79.75 % PbO
   Carbon     1.07 %  C     3.93 % CO2
   Chlorine  19.00 %  Cl   19.00 % Cl
               -   %   Cl   -4.29 % -O=Cl2   
   Oxygen     5.72 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Pb4(CO3)Cl6•(H2O)
Help on Environment: Environment: Quartz-dolomite ore vein exposed to sea water at the base of the cliff.
Help on IMA Status: IMA Status: Approved IMA 1991
Help on Locality: Locality: Bounds Cliff, St. Endellion, Cornwall, England. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Richard William Barstow (1947-1982), Cornish mineral dealer.
Help on Name Pronunciation: Name Pronunciation: Barstowite + Pronunciation Say BARSTOWITE
Help on Synonym: Synonym: ICSD 411366
  IMA1989-057
  PDF 51-1520
 

Barstowite Image

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  Barstowite

Comments: SEM images of irregular prismatic barstowite with phosgenite. (MinMag, v55:378).
Location: Lead-antimony vein at the southwestern end of Bounds Cliff, St Endellion, Cornwall, UK. Scale: Scale bar left 400 µm right 100 µm.
© Mineralogical Magazine

Barstowite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.457:1:1.8113
Help on Cell Dimensions: Cell Dimensions: a = 4.2043, b = 9.199, c = 16.663, Z = 2; beta = 91.82° V = 644.12 Den(Calc)= 5.77
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/m
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 4.02(1), 2.296(0.8), 2.377(0.6),
 

Physical Properties of Barstowite

Help on Cleavage: Cleavage: {???} Indistinct
Help on Color: Color: Colorless, White.
Help on Density: Density: 5.5 - 5.69, Average = 5.59
Help on Diaphaneity: Diaphaneity: Transparent to Opaque
Help on Fracture: Fracture: Brittle - Uneven - Very brittle fracture producing uneven fragments.
Help on Habit: Habit: Microscopic Crystals - Crystals visible only with microscopes.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Hardness: Hardness: 3 - Calcite
Help on Luster: Luster: Adamantine
Help on Streak: Streak: white
 

Optical Properties of Barstowite

Help on Optical Data: Optical Data: Biaxial (?)
  NCalc= 2.04 - from Gladstone-Dale relationship (KC = 0.1799) where Ncalc=Dcalc*KC+1
NCalc= 2.01 - from Gladstone-Dale relationship (KC = 0.1799) where Ncalc=Dmeas*KC+1
Help on RL Anisotrophism: RL Anisotrophism: Weak to moderate.
Help on RL Bireflectance: RL Bireflectance: Moderate, gray to dark gray.
Help on RL Color: RL Color: White with abundant colorless internal reflections.
Help on Reflectivity Reflectivity
Standardized Intensity (100%) Reflection Spectra of Barstowite in Air
λ R1 R2  ∑ R1(λ)   ∑ R2(λ) 
 400 nm   14.20   14.80 
   
 420 nm   14.00   14.60 
 440 nm   13.80   14.40 
 460 nm   13.70   14.10 
 480 nm   13.40   13.90 
 500 nm   13.20   13.70 
 520 nm   13.10   13.50 
 540 nm   12.90   13.40 
 560 nm   12.80   13.20 
 580 nm   12.70   13.10 
 600 nm   12.60   13.00 
 620 nm   12.50   12.90 
 640 nm   12.50   12.90 
 660 nm   12.40   12.80 
 680 nm   12.30   12.80 
 700 nm   12.30   12.70 
Calculated Relative Intensity Colors of Barstowite in Air
Relative
Intensity
   0%   70% 100% 140% 210% 280% 350% 420% 490% 560% 630% 690%
R1                        
R2                        
 

Calculated Properties of Barstowite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.84 gm/cc
note: Specific Gravity of Barstowite =5.77 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.16
Boson Index = 0.84
Help on Photoelectric: Photoelectric: PEBarstowite =1,354.95 barns/electron
U=PEBarstowite x rElectron Density=6,564.29 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Barstowite is Not Radioactive
 

Barstowite Classification

Help on  Dana Class: Dana Class: 12.01.07.01 (12)Compound Halides
  (12.01)with miscellaneous anions
  (12.01.07)Dana Group
 
12.01.07.01 Barstowite Pb4(CO3)Cl6•(H2O) P 21/m 2/m
Help on  Strunz Class: Strunz Class: 03.DC.95 03 - HALIDES
  03.D - Oxyhalides, Hydroxyhalides and Related Double Halides
  03.DC -With Pb (As,Sb,Bi), without Cu
 
03.DC.95 Barstowite Pb4(CO3)Cl6•(H2O) P 21/m 2/m
 

Other Barstowite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(AmMin, vol 86) OPTIC PROP.(AntBidBlaNic5)
Help on See Also: See Also: Links to other databases for Barstowite :
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
15 - WWW-MINCRYST

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Barstowite

Pb4(CO3)Cl6•(H2O)
Dana No: 12.01.07.01 Strunz No: 03.DC.95
Locality:

 

Notes:

 

 
   
 


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