Mineralogy Database

Armstrongite Mineral Data

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General Armstrongite Information

Help on Chemical  Formula: Chemical Formula: CaZrSi6O15•3(H2O)
Help on Composition: Composition: Molecular Weight = 593.85 gm
   Calcium     6.75 %  Ca    9.44 % CaO
   Zirconium  15.36 %  Zr   20.75 % ZrO2
   Silicon    28.38 %  Si   60.71 % SiO2
   Hydrogen    1.02 %  H     9.10 % H2O
   Oxygen     48.50 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: CaZrSi6O15•3(H2O)
Help on Environment: Environment: Not a lunar mineral. Associated with alkalic rocks.
Help on IMA Status: IMA Status: Approved IMA 1973
Help on Locality: Locality: TL:Khan-Bogdin massif, Mongolia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Neil Alden Armstrong, (1930-), American astronaut, first human being on the moon's surface, Apollo 11 Lunar Mission.
Help on Name Pronunciation: Name Pronunciation: Armstrongite + Pronunciation Say ARMSTRONGITE
Help on Synonym: Synonym: ICSD 27752
  PDF 29-395

Armstrongite Image

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Comments: Tan massive armstrongite aggregate in granite.
Location: Khan-Bogdo Massif, Gobi, Mongolia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Armstrongite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.9982:1:0.5547
Help on Cell Dimensions: Cell Dimensions: a = 14.108, b = 14.133, c = 7.84, Z = 4; beta = 109.4° V = 1,474.45 Den(Calc)= 2.68
Help on Crystal System: Crystal System: Monoclinic - Sphenoidal H-M Symbol (2) Space Group: C 2
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.05(1), 4.26(1), 6.6(0.9),

Physical Properties of Armstrongite

Help on Cleavage: Cleavage: {001} Perfect, {100} Distinct
Help on Color: Color: Light brown, Reddish brown.
Help on Density: Density: 2.7 - 2.71, Average = 2.7
Help on Diaphaneity: Diaphaneity: Translucent
Help on Fracture: Fracture: Brittle - Generally displayed by glasses and most non-metallic minerals.
Help on Habit: Habit: Aggregates - Made of numerous individual crystals or clusters.
Help on Habit: Habit: Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).
Help on Habit: Habit: Spherical - Spherical, rounded aggregates.
Help on Hardness: Hardness: 4.5 - Between Fluorite and Apatite
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: brownish white

Optical Properties of Armstrongite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.049 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.04 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2121,KPDmeas= 0.2101,KC= 0.2208
Ncalc = 1.59 - 1.6
Help on Optical Data: Optical Data: Biaxial (-), a=1.563, b=1.569, g=1.573, bire=0.0100
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.
Help on Pleochroism (z): Pleochroism (z): colorless.

Calculated Properties of Armstrongite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.65 gm/cc
note: Specific Gravity of Armstrongite =2.68 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.03
Boson Index = 0.97
Help on Photoelectric: Photoelectric: PEArmstrongite = 21.90 barns/electron
U=PEArmstrongite x rElectron Density= 58.12 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Armstrongite is Not Radioactive

Armstrongite Classification

Help on  Dana Class: Dana Class: (72)Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
  (72.05)with corrugated and complex layers
  (72.05.04)Elpidite/armstrongite Armstrongite CaZrSi6O15•3(H2O) C 2 2 Elpidite Na2ZrSi6O15•3(H2O) Pb21m mm2
Help on  Strunz Class: Strunz Class: 09.EA.35 09 - SILICATES (Germanates)
  09.E - Phyllosilicates
  09.EA -Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings
09.EA.35 Armstrongite CaZrSi6O15•3(H2O) C 2 2

Other Armstrongite Information

Help on References: References: NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990, AmMin Vol 86, p 1537) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Armstrongite :
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: 09.EA.35





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