Quasicrystals belongs to a new state of matter, whose discovery was recently awarded by the Nobel prize, which presents a long range order without translational symmetry. Major questions concern the location of the atoms, their dynamics and possible structural phase transitions. The family of icosahedral quasicrystals of Tsai type [1,2] contains binary stable i-QC with low chemical disorder that offer the opportunity of precise structural analysis [3]. Neutron scattering [4] showed evidences of a dynamics of the central symmetry-breaking tetrahedron in the periodic approximant, and the phase transition near 160K was explained by an ordering of the tetrahedra. These results raise fundamental questions about the origin of the phase transition, and the coupling between the different shells of the Tsai cluster which is the main building unit of the approximant and i-QC (Fig.1). In this presentation, we will report results of 45Sc (I=7/2) and 67Zn (I=5/2) solid-state NMR experiments at different fields, and temperatures, in the 1/1 approximant Zn6Sc and quasicrystal ZnScAg. In particular, 67Zn spectra of Zn6Sc approximant were obtained at fields up to 18.8T (Lille High Field NMR platform). Observing such a nucleus was a challenge in such metallic samples, because of its very low sensitivity (low nuclear gyromagnetic ratio, natural abundance of 4.1%, medium quadrupolar coupling). Both nuclei carry complementary information within the icosahedral cluster, composed of five successive shells of increasing radius : tetrahedron (4Zn), dodecahedron (20Zn), icosahedron (12Sc), icosidodecahedron (30Zn) and rhombic triancontahedrom (92Zn). Scandium that belongs only to the icosahedron shell are particularly well suited to probe intershell coupling and tetrahedron induced distorsions. We will discuss how NMR provides insight in the structure and dynamics of these compounds. Acknowledgements: We acknowledge IRRMN FR3050 CNRS for support of High Field NMR experiments in Lille. This research received FEDER financial support (FEDER 34722-Prin2Tan) for funding NMR spectrometers in Rennes. References [1] A. P. Tsai, J. Q. Guo, E. Abe, H. Takakura, T. J. Sato, Nature, 2000, 408, 537 [2] A.P. Tsai, Chem. Soc. Rev., 2013, 42, 5352. [3] H. Takakura, C. Pay Gomez, A. Yamamoto, M. de Boissieu, A. P. Tsai, Nat. Mater.,2007, 6,58 [4] H. Euchner et al., J Phys: Condens. Matter 24,p415403 (2012);