We present the key results from a comprehensive study of the refraction andfocusing properties of a two-dimensional dodecagonal photonic ``quasicrystal''(PQC), carried out via both full-wave numerical simulations and microwavemeasurements on a slab made of alumina rods inserted in a parallel-platewaveguide. We observe anomalous refraction and focusing in several frequencyregions, confirming some recently published results. However, ourinterpretation, based on numerical and experimental evidence, differssubstantially from the one in terms of ``effective negative refractive-index''that was originally proposed. Instead, our study highlights the critical roleplayed by short-range interactions associated with local order and symmetry.
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