Margarite Mineral Data
General Margarite Information
Chemical Formula:
CaAl2(Al2Si2)O10(OH)2
Composition:
Molecular Weight = 398.18 gm
Calcium 10.07 % Ca 14.08 % CaO
Aluminum 27.10 % Al 51.21 % Al2 O3
Silicon 14.11 % Si 30.18 % SiO2
Hydrogen 0.51 % H 4.52 % H2 O
Oxygen 48.22 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
CaAl4 Si2 O10 (OH)2
Environment:
Commonly associated with corundum as an alteration product.
IMA Status:
Valid Species (Pre-IMA) 1823
Locality:
Corundum mines at Ekaterinurg Distict, Ural Mountains, Russia. Link to MinDat.org Location Data.
Name Origin:
From the Greek margaritos - "pearl."
Name Pronunciation:
Margarite
Margarite Image
Images:
Margarite Crystallography
Axial Ratios:
a:b:c =0.5816:1:2.1774
Cell Dimensions:
a = 5.118, b = 8.799, c = 19.159, Z = 4; beta = 95.15° V = 859.31 Den(Calc)= 3.08
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c
X Ray Diffraction:
By Intensity(I/Io ): 3.18(1), 1.908(0.35), 2.517(0.25),
Physical Properties of Margarite
Cleavage:
{001} Good
Color:
White, Gray, Pinkish gray, Yellowish gray.
Density:
2.99 - 3.08, Average = 3.03
Diaphaneity:
Translucent to subtranslucent
Fracture:
Brittle - Generally displayed by glasses and most non-metallic minerals.
Habit:
Lamellar - Thin laminae producing a lamellar structure.
Habit:
Massive - Lamellar - Distinctly foliated fine-grained forms.
Habit:
Scaly - Morphology like fish scales.
Hardness:
4 - Fluorite
Luminescence:
Fluorescent, Short UV=sky blue, Long UV=strong sky blue.
Luster:
Pearly
Streak:
white
Optical Properties of Margarite
Gladstone-Dale:
CI meas = 0.028 (Excellent) - where the CI = (1-KPDmeas /KC ) CI calc = 0.042 (Good) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2047,KPDmeas = 0.2077,KC = 0.2137 Ncalc = 1.64 - 1.66
Optical Data:
Biaxial (-), a=1.595-1.638, b=1.625-1.648, g=1.627-1.65, bire=0.0120-0.0320, 2V(Calc)=28-46, 2V(Meas)=26-67. Dispersion r < v.
Pleochroism (x):
colorless.
Pleochroism (y):
colorless.
Pleochroism (z):
colorless.
Calculated Properties of Margarite
Electron Density:
Bulk Density (Electron Density)=3.02 gm/cc note: Specific Gravity of Margarite =3.04 gm/cc.
Fermion Index:
Fermion Index = 0.0069559576 Boson Index = 0.9930440424
Photoelectric:
PEMargarite = 2.58 barns/electronU=PEMargarite x r Electron Density= 7.79 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Margarite is Not Radioactive
Margarite Classification
Dana Class:
71.02.02c.01 (71) Phyllosilicate Sheets of Six-Membered Rings
(71.02) with 2:1 Layers
(71.02.02c) Mica Group (Margarite subgroup)
71.02.02c.01 Margarite CaAl2(Al2Si2)O10(OH)2 C 2/c 2/m
71.02.02c.02 Clintonite Ca(Mg,Al)3(Al3Si)O10(OH)2 C 2/m 2/m
71.02.02c.03 Bityite CaLiAl2(AlBeSi2)O10(OH)2 C 2/c 2/m
71.02.02c.04 Anandite (Ba,K)(Fe,Mg)3(Si,Al,Fe)4O10(S,OH)2 C 2/m 2/m
71.02.02c.05 Kinoshitalite (Ba,K)(Mg,Mn,Al)3Si2Al2O10(OH)2 C 2/m 2/m
71.02.02c.06 Ferrokinoshitalite ! (Ba,K)(Fe,Mg)3(Si2Al2)O10(OH,F)2 C 2/m 2/m
71.02.02c.07 Ganterite ! [Ba0.5(Na,K)0.5]Al2(Si2.5Al1.5O10)(OH)2 C 2/c 2/m
71.02.02c.08 Oxykinoshitalite ! (Ba,K)(Mg,Fe,Ti)3(Si,Al)4O10O2 C 2/m 2/m
Strunz Class:
09.EC.30 09 - SILICATES (Germanates)
09.E - Phyllosilicates
09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
09.EC.30 Margarite CaAl2(Al2Si2)O10(OH)2 C 2/c 2/m
Other Margarite Information
References:
NAME( Duda&Rejl90) PHYS. PROP.(Collectors Book of Fluorescent Minerals) OPTIC PROP.(Heinrich65)
See Also:
Links to other databases for Margarite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Franklin Minerals(Dunn)
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - HyperPhysics
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - Scandinavian mineral gallery
18 - WWW-MINCRYST
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Margarite
CaAl2(Al2Si2)O10(OH)2
Dana No: 71.02.02c.01 Strunz No: 09.EC.30
Locality:
Notes:
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