Raw materials from aquatic environments were systematically used for domestic activities even before the appearance of modern humans. Here, the authors analyse the possible use of freshwater mussel valves of the Unio species, whose surfaces preserve marks resulting from their use. They consider the ways in which wear develops on these valves, starting from the comparison between archaeological exemplars and experimental pieces. An experimental programme was developed to record variables such as the procurement of the raw material, the processing of various materials, and the time needed for each operation. Experimental pieces were assessed to document how use-wear develops. The archaeological assemblage from the site of Cheia in Romania (Hamangia culture, fifth millennium cal BC) served as a case study to illustrate the relevance of the results.