The crystallization of salt solutions is strongly affected regarding the shape of the crystalline network by the presence of impurities, even in extremelly small quantities. This sensitivity is extremely high especially for dihydrate copper chloride (DCC) solution. The phenomenon is used for early diagnostic in medicine and for food quality assessment and named sensitive crystallization or biocrystallization. The evaluation is based on the morphology of the DCC network that crystallizes on a Petri plate containing a fine film of this solution to which a small amount of the substrate analyzed is added. For this reason, the understanding of the influence of all physico-chemical factors on the crystallization of the DCC solution is very important. To help elucidate some of these aspects, we analyzed by biocrystallization a series of 30 mineral waters from Romania, following their influence on the morphology of the DCC crystallization network. This is the first paper about biocrystallization of natural mineral waters. Following this analysis we noticed specific patterns generated by the predominant chemical composition and the total mineralization of the analyzed waters. These results can be extrapolated in the medical and agro-food field, contributing to the correct interpretation of the biocrystallisation test.