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Lacroixite Mineral Data

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General Lacroixite Information

Help on Chemical  Formula: Chemical Formula: NaAl(PO4)F
Help on Composition: Composition: Molecular Weight = 163.94 gm
   Sodium      14.02 %  Na   18.90 % Na2O
   Aluminum    16.46 %  Al   31.10 % Al2O3
   Phosphorus  18.89 %  P    43.29 % P2O5
   Oxygen      39.04 %  O
   Fluorine    11.59 %  F    11.59 % F
                 -   %   F    -4.88 % -O=F2    
              ______        ______ 
              100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: NaAl(PO4)F
Help on Environment: Environment: In druses in granite.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1914
Help on Locality: Locality: Large crystals [from the Koppar quarry,] on the Greifensteine, near Ehrenfriedersdorf, Saxony, Germany. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Francois Antoine Alfred Lacroix (1863-1948), French mineralogist, Natural History Museum, Paris, France.
Help on Name Pronunciation: Name Pronunciation: Lacroixite + Pronunciation Say LACROIXITE
Help on Synonym: Synonym: ICSD 40522
  PDF 39-325

Lacroixite Image

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  Lacroixite   Berlinite

Comments: Pale olive green crystalline lacroixite with white crystalline berlinite.
Location: Rusororo Pegmatite, Gatumba, Gisenyi, Rwanda. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Lacroixite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.7815:1:0.8389
Help on Cell Dimensions: Cell Dimensions: a = 6.414, b = 8.207, c = 6.885, Z = 4; beta = 115.47° V = 327.20 Den(Calc)= 3.33
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): 2.9(1), 2.47(0.85), 3.159(0.71),

Physical Properties of Lacroixite

Help on Cleavage: Cleavage: {111} Indistinct, {111} Indistinct
Help on Color: Color: Colorless, Gray, Gray white, Light green, Light yellow.
Help on Density: Density: 3.29
Help on Hardness: Hardness: 4.5 - Between Fluorite and Apatite
Help on Luster: Luster: Vitreous - Resinous
Help on Streak: Streak: white

Optical Properties of Lacroixite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.075 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.086 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1691,KPDmeas= 0.1711,KC= 0.185
Ncalc = 1.61 - 1.62
Help on Optical Data: Optical Data: Biaxial (-), a=1.546, b=1.563, g=1.58, bire=0.0340, 2V(Calc)=88, 2V(Meas)=89.

Calculated Properties of Lacroixite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.21 gm/cc
note: Specific Gravity of Lacroixite =3.29 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0001873774
Boson Index = 0.9998126226
Help on Photoelectric: Photoelectric: PELacroixite = 1.67 barns/electron
U=PELacroixite x rElectron Density= 5.35 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Lacroixite is Not Radioactive

Lacroixite Classification

Help on  Dana Class: Dana Class: (41)Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen
  (41.05)where (A B)2 (XO4) Zq
  (41.05.05)Lacroixite Group Lacroixite NaAl(PO4)F C 2/c 2/m Durangite NaAl(AsO4)F C 2/c 2/m Maxwellite NaFe(AsO4)F Aa,A2/a Mono
Help on  Strunz Class: Strunz Class: 08.BH.10 08 - PHOSPHATES, ARSENATES, VANADATES
  08.B - Phosphates, etc. with Additional Anions, without H2O
  08.BH -With medium-sized and large cations, (OH,etc.):RO4 = 1:1
08.BH.10 Durangite NaAl(AsO4)F C 2/c 2/m
08.BH.10 Isokite CaMg(PO4)F C 2/c 2/m
08.BH.10 Lacroixite NaAl(PO4)F C 2/c 2/m
08.BH.10 Maxwellite NaFe(AsO4)F Aa,A2/a Mono
08.BH.10 Panasqueiraite CaMg(PO4)(OH,F) C 2/c 2/m
08.BH.10 Tilasite CaMg(AsO4)F C 2/c 2/m

Other Lacroixite Information

Help on References: References: NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Lacroixite :
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

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Dana No: Strunz No: 08.BH.10





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