The rich architectural Baroque heritage of the cities in the Iblean area (eastern Sicily, Southern Italy) is characterized by the presence of important monuments built using different varieties of local calcarenite such as Ragusa, Comiso, and Modica stones. Unfortunately, these materials are significantly affected by degradation processes, such as biodeterioration, favored by surrounding environmental conditions and their intrinsic characteristics. In response to these challenges, in recent years there has been growing attention on the formulation of more sustainable alternatives to traditional chemical biocides. The mineral-petrographic and physical characterization of the three stones provided important information to understand their responses to degradation processes and to define the most suitable conservation strategies. In this regard, biopolymeric membranes as controlled-release systems for natural biocides have been synthesized and tested. In this first phase of investigation, the results obtained from petrographic and ultrasonic analyses reveal similarities and differences between the three lithotypes, suggesting that their heterogeneity may influence degradation phenomena. Further mineralogical, physical, and mechanical characterization tests will be carried out in the future. FTIR results showed the presence of limonene in the biopolymer membrane. In the next steps of the research, NMR analysis will also be conducted to confirm or disprove FTIR results. In addition, new membranes will be synthesized with other molecules with antimicrobic features.