Mineralogy Database

Labradorite Mineral Data

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General Labradorite Information

Help on Chemical Formula: Chemical Formula: (Ca,Na)(Si,Al)4O8
Help on Composition: Composition: Molecular Weight = 271.81 gm
   Sodium     3.38 %  Na    4.56 % Na2O
   Calcium    8.85 %  Ca   12.38 % CaO
   Aluminum  15.88 %  Al   30.01 % Al2O3
   Silicon   24.80 %  Si   53.05 % SiO2
   Oxygen    47.09 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Na0.4Ca0.6Al1.6Si2.4O8
Help on Environment: Environment: Magmatic and metamorphic rocks.
Help on IMA Status: IMA Status: Not Approved IMA 1780
Help on Locality: Locality: Labrador peninsula, Canada. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after its locality.
Help on Name Pronunciation: Name Pronunciation: Labradorite + Pronunciation Say LABRADORITE
Help on Synonym: Synonym: Ab40
  An60
  Spectrolite
 

Labradorite Image

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

Comments: Dual view of a cleavage fragment of labradorite showing the multi-colored labradorescence (schiller effect) and the same area viewed without the color. The color is due to optical interference on Bøggild exsolution lamellae.
Location: Ihosy, Betroka district, Toliara Province, Madagascar. Scale: Picture size 3x3 cm.
© Dave Barthelmy

Labradorite Crystallography
Help on Axial Ratios: Axial Ratios: a:b:c =0.6351:1:0.7912
Help on Cell Dimensions: Cell Dimensions: a = 8.155, b = 12.84, c = 10.16, Z = 6; alpha = 93.5°, beta = 116.25°, gamma = 89.133° V = 952.25 Den(Calc)= 2.84
Help on Crystal System: Crystal System: Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: C1
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.18(1), 3.21(0.7), 3.76(0.7),
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 0 1) ( 1 0 0) ( 1 0 1) ( 0 1 0)

Warning: this java applet does not work in some browsers because of security restrictions.

 

Physical Properties of Labradorite

Help on Cleavage: Cleavage: {001} Perfect, {010} Good, {110} Distinct
Help on Color: Color: Colorless, Gray, Gray white, White, Light green.
Help on Density: Density: 2.68 - 2.71, Average = 2.69
Help on Diaphaneity: Diaphaneity: Translucent to transparent
Help on Fracture: Fracture: Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Help on Habit: Habit: Crystalline - Coarse - Occurs as well-formed coarse sized crystals.
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Habit: Habit: Striated - Parallel lines on crystal surface or cleavage face.
Help on Hardness: Hardness: 7 - Quartz
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: white
 

Optical Properties of Labradorite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.009 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.043 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1983,KPDmeas= 0.2089,KC= 0.2071
Ncalc = 1.56 - 1.59
Help on Optical Data: Optical Data: Biaxial (+), a=1.554-1.563, b=1.5588-1.5675, g=1.562-1.573, bire=0.0080-0.0100, 2V(Calc)=78-86, 2V(Meas)=85.
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.
 

Calculated Properties of Labradorite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.67 gm/cc
note: Specific Gravity of Labradorite =2.70 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PELabradorite = 2.56 barns/electron
U=PELabradorite x rElectron Density= 6.84 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Labradorite is Not Radioactive
 

Labradorite Classification
Help on Dana Class: Dana Class: 76.01.03.04 (76)Tectosilicate Al-Si Framework
  (76.01)with Al-Si frameworks
  (76.01.03)Plagioclase series
 
76.01.03.00 Plagioclase* (Na,Ca)(Si,Al)4O8 C1 1
 
76.01.03.01 Albite NaAlSi3O8 C1 1
 
76.01.03.02 Oligoclase (Na,Ca)(Si,Al)4O8 C1 1
 
76.01.03.03 Andesine* (Na,Ca)(Si,Al)4O8 C1 1
 
76.01.03.04 Labradorite* (Ca,Na)(Si,Al)4O8 C1 1
 
76.01.03.05 Bytownite* (Ca,Na)(Si,Al)4O8 C1 1
 
76.01.03.06 Anorthite CaAl2Si2O8 P1,I1 1
Help on Strunz Class: Strunz Class: 09.FA.35 09 - SILICATES (Germanates)
  09.F - Tektosilicates without Zeolitic H2O
  09.FA -Tektosilicates without additional non-tetrahedral anions, (Al,B):Si = 1:1
 
09.FA.35 Albite NaAlSi3O8 C1 1
 
09.FA.35 Bytownite* (Ca,Na)(Si,Al)4O8 C1 1
 
09.FA.35 Anorthite CaAl2Si2O8 P1,I1 1
 
09.FA.35 Andesine* (Na,Ca)(Si,Al)4O8 C1 1
 
09.FA.35 Labradorite* (Ca,Na)(Si,Al)4O8 C1 1
 
09.FA.35 Oligoclase (Na,Ca)(Si,Al)4O8 C1 1
 
09.FA.35 Reedmergnerite NaBSi3O8 C1 1
 
09.FA.35 Plagioclase* (Na,Ca)(Si,Al)4O8 C1 1
 

Other Labradorite Information
Help on See Also: See Also: Links to other databases for Labradorite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - Christie Rowe
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - GeoScienceWorld
8 - Glendale Community College
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - HyperPhysics
14 - MinDAT
15 - Mineral and Gemstone Kingdom
16 - Mineralienatlas (Deutsch)
17 - Online Mineral Museum
18 - QUT Mineral Atlas
19 - Ruff.Info
20 - Scandinavian mineral gallery
21 - Tradeshop.com - The Rainbow of Gems
22 - WWW-MINCRYST

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Labradorite

(Ca,Na)(Si,Al)4O8
Dana No: 76.01.03.04 Strunz No: 09.FA.35
Locality:

 

Notes:

 
 

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