1. A method of resonance spectroscopy for the analysis of statistical properties of samples, the method comprising the steps of: a) recording a complex resonance frequency spectrum of each sample by means of phase sensitive quadrature detection; b) numerically differentiating the recorded complex resonance frequency spectra with respect to frequency; c) determinating an absolute value of each differentiated complex resonance frequency spectrum to obtain a fingerprint; d) allocating each fingerprint to a point in a multidimensional point set; e) performing a pattern analysis of the multidimensional point set to characterize statistical properties of the samples.