Mineralogy Database

Cerchiaraite Mineral Data

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General Cerchiaraite Information

Help on Chemical  Formula: Chemical Formula: Ba4(Mn,Fe,Al)4Si6(O,OH,Cl)26
Help on Composition: Composition: Molecular Weight = 1,398.66 gm
   Barium     39.27 %  Ba   43.85 % BaO
   Manganese  13.35 %  Mn   17.24 % MnO
   Aluminum    0.58 %  Al    1.09 % Al2O3
   Iron        1.60 %  Fe    2.05 % FeO
   Silicon    12.05 %  Si   25.77 % SiO2
   Hydrogen    0.52 %  H     4.64 % H2O
   Chlorine    3.80 %  Cl    3.80 % Cl
                -   %   Cl   -0.86 % -O=Cl2   
   Oxygen     28.83 %  O
             ______        ______ 
             100.00 %       97.60 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ba4Mn2+3.4Fe2+0.4Al0.3Si6O18(OH)7.2Cl1.5
Help on Environment: Environment: Individual grains in fractures.
Help on IMA Status: IMA Status: Approved IMA 1999 (Dana # Added)
Help on Locality: Locality: Cerchiara manganese (braunite) mine, Val di Vara, eastern Liguria, Italy. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the locality.
Help on Synonym: Synonym: IMA1999-012

Cerchiaraite Image

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Comments: Green aggregates of cerchiaraite on matrix.
Location: Cerchiara Mine, Near Faggiona, Val di Vara, Eastern Liguria, Italy. Scale: Specimen Size 13x7x6 mm.
© Sergey Vasiliev / Systematic Mineralogy

Cerchiaraite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.43095
Help on Cell Dimensions: Cell Dimensions: a = 14.215, c = 6.126, Z = 2; V = 1,237.86 Den(Calc)= 3.75
Help on Crystal System: Crystal System: Tetragonal - Ditetragonal Dipyramidal H-M Symbol (4/m 2/m 2/m) Space Group: I 4/mmm
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.011(1)(411), 10.15(0.88)(110), 3.319(0.75)(321),2.619(0.74)(222), 2.577(0.62)(501), 5.63(0.5)(101), 4.417(0.49)(211),

Physical Properties of Cerchiaraite

Help on Cleavage: Cleavage: None
Help on Color: Color: Deep green.
Help on Diaphaneity: Diaphaneity: Transparent
Help on Fracture: Fracture: Brittle - Uneven - Very brittle fracture producing uneven fragments.
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Habit: Habit: Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)
Help on Hardness: Hardness: 4-5 - Fluorite-Apatite
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: pale green

Optical Properties of Cerchiaraite

Help on Gladstone-Dale: Gladstone-Dale: CI calc= -0.134 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2013,KC= 0.1776
Ncalc = 1.67
Help on Optical Data: Optical Data: Uniaxial (+), w=1.745, e=1.765, bire=0.0200.

Calculated Properties of Cerchiaraite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.44 gm/cc
note: Specific Gravity of Cerchiaraite =3.75 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.07
Boson Index = 0.93
Help on Photoelectric: Photoelectric: PECerchiaraite = 176.49 barns/electron
U=PECerchiaraite x rElectron Density= 607.19 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Cerchiaraite is Not Radioactive

Cerchiaraite Classification

Help on  Dana Class: Dana Class: (62)Cyclosilicate Eight-Membered Rings
  (62.01)with 8-memebered and larger rings
  (62.01.01)Muirite Group Muirite Ba10Ca2MnTiSi10O30(OH,Cl,F)10 P 4/mmm 4/m 2/m 2/m Cerchiaraite! Ba4(Mn,Fe,Al)4Si6(O,OH,Cl)26 I 4/mmm 4/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 09.CF.25 09 - SILICATES (Germanates)
  09.C - Cyclosilicates
  09.CF -[Si4O12]8- 4-membered single rings, with insular complex anions
09.CF.25 Cerchiaraite! Ba4(Mn,Fe,Al)4Si6(O,OH,Cl)26 I 4/mmm 4/m 2/m 2/m

Other Cerchiaraite Information

Help on References: References: NAME( AmMin, Vol 86) PHYS. PROP.(AmMin, Vol 86) OPTIC PROP.(AmMin, Vol 86)
Help on See Also: See Also: Links to other databases for Cerchiaraite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Dana No: Strunz No: 09.CF.25





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