@prefix qx8: <http://data.loterre.fr/ark:/67375/QX8> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

qx8:-VGMZFRM2-Z
  skos:prefLabel "minéral"@fr, "mineral"@en ;
  a skos:Concept ;
  skos:narrower qx8:-RST3QTHS-R .

qx8: a skos:ConceptScheme .
qx8:-RST3QTHS-R
  skos:prefLabel "smectite"@fr, "smectite"@en ;
  skos:definition "Les smectites sont un groupe de minéraux argileux, des phyllosilicates de structure TOT (ou 2:1), c'est-à dire constitués de feuillets comportant deux couches tétraédriques disposées tête-bêche, liées entre elles par des cations octaédriques. Leur composition type est A0,3D2-3T4O10Z2·nH2O, où A représente un cation interfoliaire (élément alcalin ou alcalino-terreux), D un cation octaédrique, T un cation tétraédrique, O l'oxygène et Z un anion monovalent (généralement OH-). Elles cristallisent dans le système monoclinique. On distingue les smectites dioctaédriques (beïdellite, montmorillonite, nontronite, etc.) et trioctaédriques (hectorite, saponite, etc.). (Adapté de : <a href=\"https://fr.wikipedia.org/wiki/Smectite\">https://fr.wikipedia.org/wiki/Smectite</a>)"@fr, "A smectite is a mineral mixtures of various swellable sheet silicates (phyllosilicates), which have a three-layer structure and belong to the clay minerals. Smectites consist mainly of montmorillonite, but also contain quartz and calcite dust. The three-layer structure consists of two tetrahedron layers which are electrostatically cross-linked via the cations of an octahedron intermediate layer. The layers are not rigidly connected to each other; they can swell due to the reversible incorporation of water and other substances. Smectite is produced by chemical weathering of feldspars in soils or possibly by authigenic formation in saline lakes as alteration products of volcanic materials (Jones and Weir, 1983). In particular, smectite is often an authigenic mineral formed from the weathering of basalt, but it also occurs on sediments and calcareous substrates. It occurs predominantly in drier climates and in landscapes with low relief. (Adapted from: <a href=\"https://en.wikipedia.org/wiki/Smectite\">https://en.wikipedia.org/wiki/Smectite</a> and J. P. Bradbury (1997), Quaternary Science Reviews, Vol. 16, 203-219. and R. A. Viscarra Rossel (2011), Journal of Geophysical Research Atmospheres 116(F4) : F04023.)"@en ;
  skos:exactMatch <https://fr.wikipedia.org/wiki/Smectite>, <https://en.wikipedia.org/wiki/Smectite>, <http://data.loterre.fr/ark:/67375/26L-QTWBWBV9-D> ;
  skos:broader qx8:-VGMZFRM2-Z ;
  a skos:Concept ;
  skos:inScheme qx8: .