Glauconite Mineral Data
General Glauconite Information
Chemical Formula:
(K,Na)(Fe+++,Al,Mg)2(Si,Al)4O10(OH)2
Composition:
Molecular Weight = 426.93 gm
Potassium 5.49 % K 6.62 % K2 O
Sodium 0.27 % Na 0.36 % Na2 O
Magnesium 2.28 % Mg 3.78 % MgO
Aluminum 1.90 % Al 3.58 % Al2 O3
Iron 19.62 % Fe 3.37 % FeO / 24.31 % Fe2 O3
Silicon 25.00 % Si 53.48 % SiO2
Hydrogen 0.47 % H 4.22 % H2 O
Oxygen 44.97 % O
______ ______
100.00 % 99.72 % = TOTAL OXIDE
Empirical Formula:
K0.6 Na0.05 Fe3+ 1.3 Mg0.4 Fe2+ 0.2 Al0.3 Si3.8 O10 (OH)2
Environment:
Altered from detrital biotite by marine diagenesis in shallow water under reducing conditions; especially in sandstone.
IMA Status:
Valid Species (Pre-IMA) 1828
Locality:
Otago Peninsula, New Zealand. Common world wide. Link to MinDat.org Location Data.
Name Origin:
From the Greek "glaucos" for the blue green color.
Name Pronunciation:
Glauconite + Pronunciation
Glauconite Image
Images:
Glauconite Crystallography
Axial Ratios:
a:b:c =0.5773:1:1.1206
Cell Dimensions:
a = 5.234, b = 9.066, c = 10.16, Z = 2; beta = 100.5° V = 474.03 Den(Calc)= 2.99
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
X Ray Diffraction:
By Intensity(I/Io ): 10.1(1), 2.59(1), 4.53(0.8), 1.511(0.6), 2.396(0.6), 3.33(0.6), 3.63(0.4),
Physical Properties of Glauconite
Cleavage:
{001} Perfect
Color:
Blue green, Green, Yellow green.
Density:
2.4 - 2.95, Average = 2.67
Diaphaneity:
Translucent to Subopaque
Habit:
Micaceous - Platy texture with "flexible" plates.
Hardness:
2 - Gypsum
Luminescence:
Non-fluorescent.
Luster:
Earthy (Dull)
Magnetism:
Nonmagnetic
Streak:
light green
Optical Properties of Glauconite
Gladstone-Dale:
CI meas = 0.026 (Excellent) - where the CI = (1-KPDmeas /KC ) CI calc = 0.128 (Poor) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2067,KPDmeas = 0.231,KC = 0.2371 Ncalc = 1.57 - 1.71
Optical Data:
Biaxial (-), a=1.59-1.612, b=1.609-1.643, g=1.61-1.644, bire=0.0200-0.0320, 2V(Calc)=20-24, 2V(Meas)=0-20. Dispersion r > v.
Pleochroism (x):
lemon yellow, pale yellowish green, or bright green.
Pleochroism (y):
green, dark green, yellowish green, bluish green, or olive green.
Pleochroism (z):
green, dark green, yellowish green, bluish green, or olive green.
Calculated Properties of Glauconite
Electron Density:
Bulk Density (Electron Density)=2.64 gm/cc note: Specific Gravity of Glauconite =2.68 gm/cc.
Fermion Index:
Fermion Index = 0.01 Boson Index = 0.99
Photoelectric:
PEGlauconite = 7.42 barns/electronU=PEGlauconite x r electron = 19.61 barns/cc.
Radioactivity:
GRapi = 78.31 (Gamma Ray American Petroleum Institute Units)
Concentration of Glauconite per GRapi unit = 1.28 (%)
Estimated Radioactivity from Glauconite - barely detectable
Glauconite Classification
Dana Class:
71.02.02a.05 (71) Phyllosilicate Sheets of Six-Membered Rings
(71.02) with 2:1 Layers
(71.02.02a) Mica Group (Muscovite subgroup)
71.02.02a.01 Muscovite KAl2(Si3Al)O10(OH,F)2 C 2/m 2/m
71.02.02a.02 Paragonite NaAl2(Si3Al)O10(OH)2 C 2/c,Cc Mono
71.02.02a.03 Chernykhite (Ba,Na)V,Al)2(Si,Al)4O10(OH)2 C 2/c 2/m
71.02.02a.04 Roscoelite K(V,Al,Mg)2AlSi3O10(OH)2 C 2/m 2/m
71.02.02a.05 Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2 C 2/m 2/m
71.02.02a.06 Celadonite K(Mg,Fe)(Fe,Al)[Si4O10](OH)2 C 2/m 2/m
71.02.02a.06b Ferroceladonite ! K2FeFeSi8O20(OH)4 C 2/m 2/m
71.02.02a.06c Ferroaluminoceladonite ! K2Fe2Al2Si8O20(OH)4 C 2/m 2/m
71.02.02a.06d Aluminoceladonite ! KAl(Mg,Fe)[]Si4O10(OH)2 2/m
71.02.02a.06e Chromceladonite ! KCrMg(Si4O10)(OH)2 C 2 2
71.02.02a.07 Tobelite (NH4,K)Al2(Si3Al)O10(OH)2 C 2/m 2/m
71.02.02a.08 Nanpingite Cs(Al,Mg,Fe,Li)2(Si3Al)O10(OH,F)2 C 2/c 2/m
71.02.02a.09 Boromuscovite KAl2(Si3B)O10(OH,F)2 C 2/m 2/m
71.02.02a.10 Montdorite (K,Na)(Fe,Mn,Mg)2.5[Si4O10](F,OH)2 C 2/c 2/m
71.02.02a.11 Chromphyllite ! (K,Ba)(Cr,Al)2[AlSi3O10](OH,F)2 C 2c 2/m
71.02.02a.12 Shirokshinite ! K(NaMg2)Si4O10F2 C 2/m 2/m
Strunz Class:
09.EC.15 09 - SILICATES (Germanates)
09.E - Phyllosilicates
09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
09.EC.15 Boromuscovite KAl2(Si3B)O10(OH,F)2 C 2/m 2/m
09.EC.15 Celadonite K(Mg,Fe)(Fe,Al)[Si4O10](OH)2 C 2/m 2/m
09.EC.15 Chernykhite (Ba,Na)V,Al)2(Si,Al)4O10(OH)2 C 2/c 2/m
09.EC.15 Chromphyllite ! (K,Ba)(Cr,Al)2[AlSi3O10](OH,F)2 C 2c 2/m
09.EC.15 Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2 C 2/m 2/m
09.EC.15 Aluminoceladonite ! KAl(Mg,Fe)[]Si4O10(OH)2 2/m
09.EC.15 Ferroaluminoceladonite ! K2Fe2Al2Si8O20(OH)4 C 2/m 2/m
09.EC.15 Ferroceladonite ! K2FeFeSi8O20(OH)4 C 2/m 2/m
09.EC.15 Montdorite (K,Na)(Fe,Mn,Mg)2.5[Si4O10](F,OH)2 C 2/c 2/m
09.EC.15 Nanpingite Cs(Al,Mg,Fe,Li)2(Si3Al)O10(OH,F)2 C 2/c 2/m
09.EC.15 Tobelite (NH4,K)Al2(Si3Al)O10(OH)2 C 2/m 2/m
09.EC.15 Roscoelite K(V,Al,Mg)2AlSi3O10(OH)2 C 2/m 2/m
09.EC.15 Muscovite KAl2(Si3Al)O10(OH,F)2 C 2/m 2/m
09.EC.15 Paragonite NaAl2(Si3Al)O10(OH)2 C 2/c,Cc Mono
09.EC.15 Tainiolite KLiMg2Si4O10F2 C 2/m 2/m
09.EC.15 Chromceladonite ! KCrMg(Si4O10)(OH)2 C 2 2
09.EC.15 Ganterite ! [Ba0.5(Na,K)0.5]Al2(Si2.5Al1.5O10)(OH)2 C 2/c 2/m
Other Glauconite Information
References:
NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)
See Also:
Links to other databases for Glauconite :
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 - Minerals in Thin Sections-Humboldt State
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
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Glauconite
(K,Na)(Fe+++,Al,Mg)2(Si,Al)4O10(OH)2
Dana No: 71.02.02a.05 Strunz No: 09.EC.15
Locality:
Notes:
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