This page kindly sponsored by Leslie Baker
|System:||Monoclinic||Colour:||Green, olive-green, ...|
|Hardness:||1½ - 2|
|Name:||Named in 1827 by Pierre Berthier for the type locality at Nontron, Dordogne, France. Originally named chloropal in 1822 by Dr. Johann Jacob Bernhardi and Dr. Rudolph Brandes for chlor- and opal suggesting it was a green waxy mineral somewhat resembling common opal.|
Classification of Nontronite
|Strunz 8th edition ID:||8/H.19-40|
|Nickel-Strunz 10th (pending) edition ID:||9.EC.40|
9 : SILICATES (Germanates)
E : Phyllosilicates
C : Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
|Dana 8th edition ID:||71.3.1a.3|
71 : PHYLLOSILICATES Sheets of Six-Membered Rings
3 : Sheets of 6-membered rings with 2:1 clays
|Hey's CIM Ref.:||16.18.1|
16 : Silicates Containing Aluminum and other Metals
18 : Aluminosilicates of Fe and alkalis
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Type Occurrence of Nontronite
|Type Locality:||Saint-Pardoux-la-Rivière, Dordogne, Aquitaine, France|
|Year of Discovery:||1827|
Physical Properties of Nontronite
|Lustre:||Resinous, Waxy, Dull|
|Colour:||Green, olive-green, yellow-green, yellow, orange, brown|
|Hardness (Mohs):||1½ - 2|
Crystallography of Nontronite
|Cell Parameters:||a = 5.23Å, b = 9.11Å, c = 15.5Å|
β = 90°
|Ratio:||a:b:c = 0.574 : 1 : 1.701|
|Unit Cell Volume:||V 738.50 Å³ (Calculated from Unit Cell)|
Optical Data of Nontronite
|RI values:||nα = 1.530 - 1.580 nβ = 1.555 - 1.612 nγ = 1.560 - 1.615|
|2V:||Measured: 5° to 66°, Calculated: 32° to 46°|
|Maximum Birefringence:||δ = 0.030 - 0.035|
Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
|Dispersion:||r > v strong|
Chemical Properties of Nontronite
|Essential elements:||Fe, H, Na, O, Si|
|All elements listed in formula:||Al, Fe, H, Na, O, Si|
Relationship of Nontronite to other Species
|Member of:||Smectite Group|
|Other Members of Group:|
|Related Minerals - Nickel-Strunz Grouping):|
|Related Minerals - Hey's Index Grouping:|
Other Names for Nontronite
|Health Warning:||No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.|
References for Nontronite
Larsen, Esper Signius & George Steiger (1928), Dehydration and optical studies of alunogen, nontronite, and griffithite: American Journal of Science, 5th. series: 15: 1-19.
Russell, J.D. and D.R. Clarke (1978), The effect of Fe-for-Si substitution on the b-dimension of nontronite: Clay Minerals: 13: 133-137.
Tsipursky, S.I., V.A. Drits, and S.S. Chekin (1978), Study of structural ordering of nontronite by oblique texture electron diffraction. Izvestiya Akademii Nauk SSSR, Seriya Geologicheskaya: 10: 105-113 (in Russian).
Besson, G., A.S. Bookin, L.G. Dainyak, M. Rautureau, S.I. Tsipursky, C. Tchoubar, and V.A. Drits (1983), Use of diffraction and Mössbauer methods for the structural and crystallochemical characterizations of nontronites: Journal of Applied Crystallography: 16: 374-383.
Aufschuss (1983): 34: 295.
Dainyak, L.G., and V.A. Drits (1987), Interpretation of Mössbauer spectra of nontronite, celadonite, and glauconite: Clays and Clay Minerals: 35: 363-372.
American Mineralogist (1988): 73: 1346.
Köster, H.M., U. Ehrlicher, H.A. Gilg, R. Jordan, E. Murad, and K. Onnich (1999), Mineralogical and chemical characteristics of five nontronites and Fe-rich smectites: Cay Minerals: 34: 579-599.
Manceau, A., B. Lanson, V.A. Drits, D. Chateigner, W.P. Gates, J. Wu, D. Huo, and J.W. Stucki (2001), Oxidation-reduction mechanism of iron in dioctahedral smectites. I. Crystal chemistry of oxidized reference nontronites: American Mineralogist: 85: 133-152.
Internet Links for Nontronite
Localities for Nontronite
The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.