inosilicate en ruban

CONT: Les inosilicates (du grec «inos», fibre) [...] peuvent être en chaîne ou en ruban. Dans le premier cas, un seul oxygène est commun à deux tétraèdres voisins. [...] Cette formule est réalisée chez les pyroxènes [...] Les inosilicates en ruban sont représentés par les amphiboles [...]

OBS: inosilicate (chain silicate, band silicate). ... Two important groups of rock-forming minerals are included: pyroxenes, where two of the four oxygens are shared to give a 'single chain' structure with the ratio Si : O = 1 : 3; and amphiboles, where half the SiO[subscript]4 tetrahedra share two oxygens and the other half share three oxygens, to give a 'double chain' or 'band' structure and a ratio Si : O = 4 : 11.
OBS: inosilicate: A class or structural type of silicate characterized by the linkage of the SiO[subscript]4 tetrahedra into linear chains by the sharing of oxygens. In a simple chain, e.g. pyroxenes, two oxygens are shared; in a double chain or band, e.g. amphiboles, half the SiO[subscript]4 tetrahedra share three oxygens and the other half share two. The Si:O ratio of the former type is 1:3 and for the latter it is 4:11.