nontroniten.
/ˈnɒntrənʌɪt/, U.S. /ˈnɑntrəˌnaɪt/ Mineralogy.
A pale yellow or greenish crystalline clay mineral, Na0.33Fe23+(Si,Al)4O10(OH)2, belonging to the smectite or montmorillonite group and sometimes resembling opal. Also called chloropal.
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the world > the earth > minerals > types of mineral > silicates > phyllosilicate > [noun] > smectites > nontronite
pinguite1831
nontronite1832
fettbol1835
volkonskoite1844
gramenite1858
morencite1904
1832 C. U. Shepard Treat. Mineral. 246 Nontronite... Soft; opake: unctuous and tender.
1875 G. J. Brush Man. Determinative Mineral. (ed. 2) Index 101 Nontronite = Chloropal.
1928 Amer. Jrnl. Sci. 215 10 A large number of names have been proposed for the hydrous silicates of ferric iron; and of these nontronite, chloropal, pinguite, fettbol, and graminite are recognized by most mineralogists as belonging to the species nontronite.
1963 M. H. Hey App. to 2nd Ed. of Index Mineral Species 117 Nontronite... The older name Chloropal has passed out of common use.
1988 Nature 6 Oct. 532/2 The lavas in the two vent fields are mantled with red-orange ‘nontronite’ deposits, an assemblage of varying amounts of iron oxides, silica and iron-rich smectite.
1993 A. M. Clark Hey's Mineral Index (ed. 3) 499/2 The name nontronite was accepted by the IMA Commission, although chloropal has priority.
This entry has been updated (OED Third Edition, December 2003; most recently modified version published online March 2022).
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