Armstrongite Mineral Data
General Armstrongite Information
Chemical Formula:
CaZrSi6O15•3(H2O)
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 % H2 O
Oxygen 48.50 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
CaZrSi6 O15 •3(H2 O)
Environment:
Not a lunar mineral. Associated with alkalic rocks.
IMA Status:
Approved IMA 1973
Locality:
TL:Khan-Bogdin massif, Mongolia. Link to MinDat.org Location Data.
Name Origin:
Named for Neil Alden Armstrong, (1930-), American astronaut, first human being on the moon's surface, Apollo 11 Lunar Mission.
Name Pronunciation:
Armstrongite + Pronunciation
Synonym:
ICSD 27752
PDF 29-395
Armstrongite Image
Images:
Armstrongite Crystallography
Axial Ratios:
a:b:c =0.9982:1:0.5547
Cell Dimensions:
a = 14.108, b = 14.133, c = 7.84, Z = 4; beta = 109.4° V = 1,474.45 Den(Calc)= 2.68
Crystal System:
Monoclinic - Sphenoidal H-M Symbol (2) Space Group: C 2
X Ray Diffraction:
By Intensity(I/Io ): 3.05(1), 4.26(1), 6.6(0.9),
Physical Properties of Armstrongite
Cleavage:
{001} Perfect, {100} Distinct
Color:
Light brown, Reddish brown.
Density:
2.7 - 2.71, Average = 2.7
Diaphaneity:
Translucent
Fracture:
Brittle - Generally displayed by glasses and most non-metallic minerals.
Habit:
Aggregates - Made of numerous individual crystals or clusters.
Habit:
Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).
Habit:
Spherical - Spherical, rounded aggregates.
Hardness:
4.5 - Between Fluorite and Apatite
Luster:
Vitreous (Glassy)
Streak:
brownish white
Optical Properties of Armstrongite
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
Optical Data:
Biaxial (-), a=1.563, b=1.569, g=1.573, bire=0.0100
Pleochroism (x):
colorless.
Pleochroism (y):
colorless.
Pleochroism (z):
colorless.
Calculated Properties of Armstrongite
Electron Density:
Bulk Density (Electron Density)=2.65 gm/cc note: Specific Gravity of Armstrongite =2.68 gm/cc.
Fermion Index:
Fermion Index = 0.03 Boson Index = 0.97
Photoelectric:
PEArmstrongite = 21.90 barns/electronU=PEArmstrongite x r Electron Density= 58.12 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Armstrongite is Not Radioactive
Armstrongite Classification
Dana Class:
72.05.04.01 (72) Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
(72.05) with corrugated and complex layers
(72.05.04) Elpidite/armstrongite
72.05.04.01 Armstrongite CaZrSi6O15•3(H2O) C 2 2
72.05.04.02 Elpidite Na2ZrSi6O15•3(H2O) Pb21m mm2
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
References:
NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990, AmMin Vol 86, p 1537) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
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
15 - WWW-MINCRYST
Search for Armstrongite using:
[AOL ]
[Bing ]
[Dog Pile ]
[GeoScienceWorld ]
[HotBot ]
[Ixquick ]
[Lycos ]
[MAMMA ]
[Scirus ]
[Teoma ]
[WebCrawler ]
[Wikipedia ]
[YAHOO ]
Visit our Advertisers for Armstrongite :
Ask about Armstrongite 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
Espa�ol
Print or Cut-and-Paste your Armstrongite Specimen Label here :
Armstrongite
CaZrSi6O15•3(H2O)
Dana No: 72.05.04.01 Strunz No: 09.EA.35
Locality:
Notes:
Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.