To compare sample data from x-ray diffraction a suitable metric is developed to evaluate the similarity (or dissimilarity) between samples and to compare it to a references. The methodology focuses on the d-lines and uses the intensity measurements indirectly in the algorithm. The resulting d-line distribution and summary statistics of the differences is used to establish whether a true difference exist between a reference and sample material. The application of the methodology was then applied to real XRPD data. The methodology was able to correctly distinguish each of the samples from the published reference source. Further refinement of the methodology and future research is highlighted to further tolerate peak shifts.