We present scanning near field microscopy and local spectroscopic characterisation of gold nanoparticles fabricated on glass sodalime cover slides. The nanoislands are fabricated by the thermal annealing of gold thin films. Results are presented for samples annealed at 300 degrees C, 400 degrees C, and 500 degrees C. We study the spectral dependence of the transmittance at the nanoscale level with respect to the nanoislands size, shape, and interparticle distance employing a Scanning Near-field Optical Microscopy. (C) 2013 AIP Publishing LLC.