Griffithite Mineral Data

Griffithite Mineral Data
Search Webmineral :
   
Home Crystal jmol jPOWD Chem X Ray Dana Strunz Properties A to Z Images Share
      News Help About


General Griffithite Information

Help on Chemical Formula: Chemical Formula: 4(Mg,Fe,Ca)O.(Al,Fe)2O3.5SiO2•7(H2O)
Help on Composition: Composition: Molecular Weight = 764.30 gm
   Calcium     2.10 %  Ca    2.93 % CaO
   Magnesium   7.63 %  Mg   12.66 % MgO
   Aluminum    5.30 %  Al   10.01 % Al2O3
   Iron       12.42 %  Fe   11.28 % FeO /  5.22 % Fe2O3
   Silicon    18.37 %  Si   39.31 % SiO2
   Hydrogen    1.85 %  H    16.50 % H2O
   Oxygen     52.33 %  O
             ______        ______ 
             100.00 %       97.91 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mg2.4Fe2+1.2Ca0.4Al1.5Fe3+0.5Si5O18·7(H2O)
Help on Environment: Environment: Amygdaloidal cavities in basalt. A variety of ferroan saponite.
Help on IMA Status: IMA Status: Not Approved IMA
Help on Locality: Locality: Cahuenga Pass, Griffith Park, Los Angeles, California, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after its locality.
 

Search for Griffithite Images

Click Here To Search Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.
  

Griffithite Crystallography
Help on Crystal System: Crystal System: Monoclinic
 

Physical Properties of Griffithite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: Dark green.
Help on Density: Density: 2.31
Help on Diaphaneity: Diaphaneity: Subtransparent to subtranslucent
Help on Habit: Habit: Platy - Sheet forms (e.g. micas).
Help on Hardness: Hardness: 1 - Talc
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous - Dull
Help on Magnetism: Magnetism: Magnetic after heating
Help on Streak: Streak: green
 

Optical Properties of Griffithite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.028 (Excellent) - where the CI = (1-KPDmeas/KC)
KPDmeas= 0.2341,KC= 0.2277
Ncalc = 1.53
Help on Optical Data: Optical Data: Biaxial (-), a=1.485, b=1.565, g=1.572, bire=0.0870
Help on Pleochroism (x): Pleochroism (x): pale yellow.
Help on Pleochroism (y): Pleochroism (y): olive green.
Help on Pleochroism (z): Pleochroism (z): brownish green.
 

Calculated Properties of Griffithite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.32 gm/cc
note: Specific Gravity of Griffithite =2.31 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEGriffithite = 4.93 barns/electron
U=PEGriffithite x rElectron Density= 11.46 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Griffithite is Not Radioactive
 

Griffithite Classification
Help on Dana Class: Dana Class: 71.00.00.00 (71)Phyllosilicate Minerals
  (71.00)Without Dana Classification Numbers
  (71.00.00)Chlorite Group
 
71.00.00.00 Bariumbannisterite* (K,H3O)(Ba,Ca)(Mn,Fe,Mg)21(Si,Al)32O80(O,OH)16•4-12(H2O) Mono
 
71.00.00.00 Ekmanite? (Fe,Mg,Mn,Fe)3(Si,Al)4O10(OH)2•2(H2O) Unk Ortho
 
71.00.00.00 Griffithite* 4(Mg,Fe,Ca)O.(Al,Fe)2O3.5SiO2•7(H2O) Mono
 
71.00.00.00 Orlovite KLi2TiSi4O11F C 2 2
 
71.00.00.00 Shlykovite KCa[Si4O9(OH)]•3H2O P 21/c 2/m
 
71.00.00.00 Spodiophyllite? (Na,K)4(Mg,Fe)3(Fe,Al)2(Si8O24) Mono
 
71.00.00.00 Voloshinite Rb(LiAl1.5[]0.5)(Al0.5Si3.5)O10F2 C 2/c 2/m
Help on Strunz Class: Strunz Class: 09.EC.45 09 - SILICATES (Germanates)
  09.E - Phyllosilicates
  09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
 
09.EC.45 Griffithite* 4(Mg,Fe,Ca)O.(Al,Fe)2O3.5SiO2•7(H2O) Mono
 
09.EC.45 Hectorite Na0,3(Mg,Li)3Si4O10(OH)2 C 2/m 2/m
 
09.EC.45 Swinefordite (Li,Ca0.5,Na)0.72(Li,Al,Mg)2.66(Si,Al)4O10(OH,F)2•2(H2O) C 2/m (MON or ORTH) 2/m
 
09.EC.45 Zincsilite Zn3Si4O10(OH)2•4(H2O)(?) C 2/m ? 2/m
 
09.EC.45 Saponite (Ca/2,Na)0,3(Mg,Fe)3(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m
 
09.EC.45 Sauconite Na0,3Zn3(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m
 
09.EC.45 Spadaite MgSiO2(OH)2•(H2O)(?) Ortho
 
09.EC.45 Sobotkite? (K,Ca0.5)0.33(Mg,Al)3(Si3Al)O10(OH)2•1-5(H2O) Unk. Mono
 
09.EC.45 Stevensite (Ca0.5,Na)0.33(Mg,Fe)3Si4O10(OH)2•n(H2O) Unk (ORTH ?) Mono
 
09.EC.45 Ferrosaponite! Ca0.3(Fe,Mg,Fe)3(Si,Al)4O10(OH)2•4(H2O) C? Mono
 

Other Griffithite Information
Help on References: References: NAME( Ford32) PHYS. PROP.(Dana) OPTIC PROP.(Ford32)
Help on See Also: See Also: Links to other databases for Griffithite :
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

Search for Griffithite using:

Google
 
Web webmineral.com
[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Griffithite :

A Bijoux Google Search for Griffithite
Adam's Minerals Google Search for Griffithite
Cape Minerals Google Search for Griffithite
Dakota Matrix Minerals Google Search for Griffithite
Excalibur Mineral Corp. Google Search for Griffithite
Exceptional Minerals Google Search for Griffithite
John Betts Fine Minerals Search for Griffithite
McDougall Minerals Google Search for Griffithite
Mineral News Website Link
Rock and Mineral Shows Google Search for Griffithite
Weinrich Minerals, Inc. Google Search for Griffithite

Ask about Griffithite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Espaņol

Print or Cut-and-Paste your Griffithite Specimen Label here :

Griffithite

4(Mg,Fe,Ca)O.(Al,Fe)2O3.5SiO2•7(H2O)
Dana No: 71.00.00.00 Strunz No: 09.EC.45
Locality:

 

Notes: