Input interpretation
nontronite (mineral)
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General properties
alternate names | hydroferripyrophyllite formula | Na_0.3Fe^(3+)_2(Si, Al)_4O_10(OH)_2·n(H_2O) discovery year | 1827
Basic properties
density | 2.3 g/cm^3 transparency | subopaque birefringence | 0.0325 luster | earthy | dull Mohs hardness | 1.75 streak | white magnetism | nonmagnetic color | greenish yellow | brownish green | olive green fracture | earthy molar mass | 495.9 g/mol (grams per mole)
Units
Mineral identifiers
Strunz ID | VIII/H.19-40 Dana ID | 71.3.1a.3 MSH number | UK-29
Crystallographic properties
crystal system | monoclinic crystal class | 2/m unit cell volume | 722.6 Å^3 (cubic ångströms) d-spacing | 1.52 Å (ångströms) | 4.56 Å (ångströms) | 15.4 Å (ångströms) intensity | 100% | 100% | 100% molecules per unit cell | 2 molecules per cell 2V angle | 71 π/360 radians≈71/2° (degrees) refractive indices | 1.555 | 1.584 | 1.588 | 0 | 0 | 0 dispersion | r > v | strong unit cell lengths | 5.23 Å (ångströms) | 9.11 Å (ångströms) | 15.25 Å (ångströms) unit cell angles | 90° (degrees) | 96° (degrees) | 90° (degrees)
Wikipedia summary
Nontronite is the iron(III) rich member of the smectite group of clay minerals. Nontronites typically have a chemical composition consisting of more than ~30% Fe_2O_3 and less than ~12% Al_2O_3 (ignited basis). Nontronite has very few economic deposits like montmorillonite Like montmorillonite, nontronite can have variable amounts of adsorbed water associated with the interlayer surfaces and the exchange cations.