Mineralogy Database

Eudidymite Mineral Data

Search Webmineral :

General Eudidymite Information

Help on Chemical  Formula: Chemical Formula: NaBeSi3O7(OH)
Help on Composition: Composition: Molecular Weight = 245.26 gm
   Sodium      9.37 %  Na   12.64 % Na2O
   Beryllium   3.67 %  Be   10.20 % BeO
   Silicon    34.35 %  Si   73.49 % SiO2
   Hydrogen    0.41 %  H     3.67 % H2O
   Oxygen     52.19 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: NaBe(Si3O7)(OH)
Help on Environment: Environment: A late-stage mineral in alkalic nepheline syenite pegmatites.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1887
Help on Locality: Locality: Island Ovre-Aro, Langesundfiord, Norway. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek for well and twinned, in allusion to its common occurrence in twins.
Help on Name Pronunciation: Name Pronunciation: Eudidymite + Pronunciation Say EUDIDYMITE
Help on Synonym: Synonym: ICSD 26001
  PDF 14-201

Eudidymite Image

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

  Eudidymite   Epididymite

Comments: Translucent prismatic crystals of eudidymite on white opaque epididymite.
Location: Narsaarsuk, Greenland. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Eudidymite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.7127:1:1.8997
Help on Cell Dimensions: Cell Dimensions: a = 12.64, b = 7.38, c = 14.02, Z = 8; beta = 103.7° V = 1,270.62 Den(Calc)= 2.56
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): 3.163(1), 3.074(0.8), 3.398(0.8),

Physical Properties of Eudidymite

Help on Cleavage: Cleavage: {001} Good, {551} Good
Help on Color: Color: Blue, Colorless, Violet, Gray, Yellow.
Help on Density: Density: 2.553
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Brittle - Generally displayed by glasses and most non-metallic minerals.
Help on Habit: Habit: Tabular - Form dimensions are thin in one direction.
Help on Habit: Habit: Twinning Common - Crystals are usually twinned.
Help on Hardness: Hardness: 6 - Orthoclase
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white

Optical Properties of Eudidymite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.003 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2138,KPDmeas= 0.2144,KC= 0.2138
Ncalc = 1.55
Help on Optical Data: Optical Data: Biaxial (+), a=1.545, b=1.546, g=1.551, bire=0.0060, 2V(Calc)=50, 2V(Meas)=30. Dispersion r > v distinct.
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.
Help on Pleochroism (z): Pleochroism (z): colorless.

Calculated Properties of Eudidymite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.55 gm/cc
note: Specific Gravity of Eudidymite =2.56 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.05
Boson Index = 0.95
Help on Photoelectric: Photoelectric: PEEudidymite = 1.51 barns/electron
U=PEEudidymite x rElectron Density= 3.85 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Eudidymite is Not Radioactive

Eudidymite Classification

Help on  Dana Class: Dana Class: (66)Inosilicate Double-Width Unbranched Chains, W=2
  (66.03)with chains P>2
  (66.03.01)P=3 Xonotlite Ca6Si6O17(OH)2 P 2/a 2/m Zorite Na6Ti5[Si12O34](O,OH)5•11(H2O) C mmm 2/m 2/m 2/m Eudidymite NaBeSi3O7(OH) C 2/c 2/m Epididymite NaBeSi3O7(OH) Pnam 2/m 2/m 2/m Yuksporite (Sr,Ba)2K4(Ca,Na)14([],Mn,Fe){(Ti,Nb)4(O,OH)4[Si6O17]2[Si2O7]3}(H2O,OH)n,n~3 P 21/m 2/m Haineaultite! (Na,Ca)5Ca(Ti,Nb)5(Si,S)12O34(OH,F)8•5(H2O) C 222 2 2 2 Chivruaiite! Ca4(Ti,Nb)5[(Si6O17)2[(OH,O)5]•13-14H2O C mmm 2/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 09.DG.60 09 - SILICATES (Germanates)
  09.D - Inosilicates* Structural terminology according to Liebau (1985)
  09.DG -Inosilicates with 3-periodic single and multiple chains
09.DG.60 Eudidymite NaBeSi3O7(OH) C 2/c 2/m

Other Eudidymite Information

Help on References: References: NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)
Help on See Also: See Also: Links to other databases for Eudidymite :
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 - GeoScienceWorld
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - MinDAT
14 - Mineralienatlas (Deutsch)
15 - Online Mineral Museum
16 - QUT Mineral Atlas
17 - Ruff.Info

Search for Eudidymite using:

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

Visit our Advertisers for Eudidymite :

Ask about Eudidymite 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 Eudidymite Specimen Label here :


Dana No: Strunz No: 09.DG.60





Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.