Mineralogy Database

Walstromite Mineral Data

Search Webmineral :

General Walstromite Information

Help on Chemical  Formula: Chemical Formula: BaCa2Si3O9
Help on Composition: Composition: Molecular Weight = 445.73 gm
   Barium   30.81 %  Ba   34.40 % BaO
   Calcium  17.98 %  Ca   25.16 % CaO
   Silicon  18.90 %  Si   40.44 % SiO2
   Oxygen   32.31 %  O
           ______        ______ 
           100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: BaCa2Si3O9
Help on Environment: Environment: Metamorphosed metasediments.
Help on IMA Status: IMA Status: Approved IMA 1965
Help on Locality: Locality: Big Creek - Rush Creek sanbornite deposit, 5 miles NE of Trimmer, Fresno Co., California. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Robert E. Walstrom (1920-), American mineral collector, who discovered the mineral.
Help on Name Pronunciation: Name Pronunciation: Walstromite + Pronunciation Say WALSTROMITE

Walstromite Image

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


Comments: Colorless massive walstromite with pronounced cleavage, showing strong orange-pink fluorescence under long-wave ultraviolet light in inset image.
Location: Esquire number 8 mine, Big Creek, Fresno County, California, USA. Scale: See Image.
© Rruff Database

Walstromite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.6991:1:0.7001
Help on Cell Dimensions: Cell Dimensions: a = 6.723, b = 9.616, c = 6.733, Z = 2; alpha = 83.1°, beta = 77.67°, gamma = 69.62° V = 395.73 Den(Calc)= 3.74
Help on Crystal System: Crystal System: Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.99(1), 2.7(0.2), 6.58(0.2),

Physical Properties of Walstromite

Help on Cleavage: Cleavage: {011} Perfect, {010} Perfect, {100} Very Good
Help on Color: Color: Colorless, White.
Help on Density: Density: 3.67
Help on Diaphaneity: Diaphaneity: Transparent
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Hardness: Hardness: 3.5 - Copper Penny
Help on Luminescence: Luminescence: Fluorescent, Short UV=pale pink, Long UV=pinkish orange.
Help on Luster: Luster: Vitreous - Pearly
Help on Streak: Streak: white

Optical Properties of Walstromite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.022 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.009 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1825,KPDmeas= 0.185,KC= 0.181
Ncalc = 1.66 - 1.67
Help on Optical Data: Optical Data: Biaxial (-), a=1.668, b=1.684, g=1.685, bire=0.0170, 2V(Calc)=26, 2V(Meas)=30. Dispersion weak.
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.
Help on Pleochroism (z): Pleochroism (z): colorless.

Calculated Properties of Walstromite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.51 gm/cc
note: Specific Gravity of Walstromite =3.72 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.06
Boson Index = 0.94
Help on Photoelectric: Photoelectric: PEWalstromite = 134.15 barns/electron
U=PEWalstromite x rElectron Density= 470.24 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Walstromite is Not Radioactive

Walstromite Classification

Help on  Dana Class: Dana Class: (59)Cyclosilicate Three-Membered Rings
  (59.01)anhydrous, no other anions
  (59.01.02)Walstromite group Walstromite BaCa2Si3O9 P1 1 Margarosanite Pb(Ca,Mn)2Si3O9 P1 1
Help on  Strunz Class: Strunz Class: 09.CA.25 09 - SILICATES (Germanates)
  09.C - Cyclosilicates
  09.CA -[Si3O9]6- 3-membered single rings (dreier-Einfachringe),
09.CA.25 Margarosanite Pb(Ca,Mn)2Si3O9 P1 1
09.CA.25 Walstromite BaCa2Si3O9 P1 1

Other Walstromite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Walstromite :
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

Search for Walstromite using:

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

Visit our Advertisers for Walstromite :

Ask about Walstromite 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 Walstromite Specimen Label here :


Dana No: Strunz No: 09.CA.25





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