Prehnite Mineral Data

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


General Prehnite Information

Help on Chemical Formula: Chemical Formula: Ca2Al2Si3O10(OH)2
Help on Composition: Composition: Molecular Weight = 395.38 gm
   Calcium   20.27 %  Ca   28.37 % CaO
   Aluminum  13.65 %  Al   25.79 % Al2O3
   Silicon   21.31 %  Si   45.59 % SiO2
   Hydrogen   0.25 %  H     2.28 % H2O
   Oxygen    44.51 %  O
            ______        ______ 
            100.00 %      102.02 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca2Al2Si3O10(OH)
Help on Environment: Environment: Hydrothermally altered rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1789
Help on Locality: Locality: Haslach, Harzburg and Oberstein, Germany. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after the Dutch Colonel, H. Von Prehn (1733-1785).
Help on Name Pronunciation: Name Pronunciation: Prehnite Say PREHNITE
Help on Synonym: Synonym: ICSD 69402
  PDF 29-290
 

Prehnite Image

Click Here for Larger Prehnite Image in a New Browser Window Images:
Click Here for Larger Prehnite Image

Prehnite

Comments: Very lustrous and brilliant prehnite.
Location: Deep Sahara, Morocco: Djbel Melh, Bou-Arfa. Scale: 9 x 6.5 cm.
© Fabre Minerals

Prehnite Crystallography
Help on Axial Ratios: Axial Ratios: a:b:c =0.8427:1:3.3784
Help on Cell Dimensions: Cell Dimensions: a = 4.61, b = 5.47, c = 18.48, Z = 2; V = 466.00 Den(Calc)= 2.82
Help on Crystal System: Crystal System: Orthorhombic - PyramidalH-M Symbol (mm2) Space Group: P 2cm
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.55(1), 3.08(1), 3.48(0.9),
Help on Forms: Forms:

Mouse
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize
Keyboard
S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu
Help on Above

Forms: ( 0 1 1) ( 1 1 0) ( 1 0 0) ( 0 0 1)

Warning: this large pop-up is very compute intensive and may not work well with some computers.
Click Here for Large Prehnite Structure Window Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
 Help on Above


Papike J J , Zoltai T , American Mineralogist , 52 (1967) p.974-984, Ordering of tetrahedral aluminium in prehnite, Ca2(Al,Fe)[Si3AlO10](OH)2

View Additional jPOWD Structure files for Prehnite
[1]
 

Physical Properties of Prehnite

Help on Cleavage: Cleavage: {001} Distinct
Help on Color: Color: Colorless, Gray, Yellow, Yellow green, White.
Help on Density: Density: 2.8 - 2.95, Average = 2.87
Help on Diaphaneity: Diaphaneity: Subtransparent to translucent
Help on Fracture: Fracture: Brittle - Generally displayed by glasses and most non-metallic minerals.
Help on Habit: Habit: Globular - Spherical, or nearly so, rounded forms (e.g. wavellite).
Help on Habit: Habit: Reniform - "Kidney like" in shape (e.g.. hematite).
Help on Habit: Habit: Stalactitic - Shaped like pendant columns as stalactites or stalagmites (e.g. calcite).
Help on Hardness: Hardness: 6-6.5 - Orthoclase-Pyrite
Help on Luminescence: Luminescence: Fluorescent, Short UV=blue white mild peach, Long UV=yellow.
Help on Luster: Luster: Vitreous - Pearly
Help on Streak: Streak: colorless
 

Optical Properties of Prehnite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.025 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.045 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2252,KPDmeas= 0.2209,KC= 0.2155
Ncalc = 1.6 - 1.64
Help on Optical Data: Optical Data: Biaxial (+), a=1.61-1.637, b=1.615-1.647, g=1.632-1.67, bire=0.0220-0.0330, 2V(Calc)=58-68, 2V(Meas)=64-70. Dispersion weak, r > v.
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.
 

Calculated Properties of Prehnite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.86 gm/cc
note: Specific Gravity of Prehnite =2.88 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEPrehnite = 3.70 barns/electron
U=PEPrehnite x rElectron Density= 10.60 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Prehnite is Not Radioactive
 

Prehnite Classification
Help on Dana Class: Dana Class: 72.01.03.01 (72)Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
  (72.01)with 4-membered rings
  (72.01.03)Dana Group
 
72.01.03.01 Prehnite Ca2Al2Si3O10(OH)2 P 2cm mm2
Help on Strunz Class: Strunz Class: 09.DP.20 09 - SILICATES (Germanates)
  09.D - Inosilicates* Structural terminology according to Liebau (1985)
  09.DP -Transitional ino-phyllosilicate structures
 
09.DP.20 Prehnite Ca2Al2Si3O10(OH)2 P 2cm mm2
 

Other Prehnite Information
Help on See Also: See Also: Links to other databases for Prehnite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Amethyst Galleries' Mineral Gallery
5 - Athena
6 - EUROmin Project
7 - Ecole des Mines de Paris
8 - Franklin Minerals(Dunn)
9 - Franklin Minerals(Palache)
10 - GeoScienceWorld
11 - Google Images
12 - Google Scholar
13 - Handbook of Mineralogy (MinSocAm)
14 - Handbook of Mineralogy (UofA)
15 - MinDAT
16 - Mineralienatlas (Deutsch)
17 - Minerals in Thin Sections-Humboldt State
18 - Online Mineral Museum
19 - QUT Mineral Atlas
20 - Ruff.Info
21 - Scandinavian mineral gallery
22 - Tradeshop.com - The Rainbow of Gems
23 - UCLA - Petrography Thin-Sections
24 - WWW-MINCRYST
25 - theimage

Search for Prehnite using:

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

Visit our Advertisers for Prehnite :

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

Ask about Prehnite 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 Prehnite Specimen Label here :

Prehnite

Ca2Al2Si3O10(OH)2
Dana No: 72.01.03.01 Strunz No: 09.DP.20
Locality:

 

Notes: