## 3 Results and Discussion
### The Determination of the Microclimate Characteristics  
In order to protect the artifacts of the cultural and natural heritage, the internal microclimate must be kept as much as possible within the accepted limits, avoiding large and frequent fluctuations. Regarding objects created from stone, they fall into a broader category of artifacts, which are individualized by the need to regulate the internal microclimate between 15 and 25 \({}^{\circ}\)C in terms of T, with fluctuations of a maximum of \(\pm\)4 \({}^{\circ}\)C during 24 h [55]. Lower Ts are preferable to slow chemical reactions that can damage materials. For RH, a range of 40-60% is recommended, with a maximum fluctuation of \(\pm\)5% during 24 h. Stable RH values are crucial to prevent damage through the expansion and contraction of materials [56]. Regarding the present study, T varies within a gap of 20.6 \({}^{\circ}\)C, ranging from a minimum of 3.9 \({}^{\circ}\)C to a maximum of 24.5 \({}^{\circ}\)C; the average over the entire monitoring period is 9.8 \({}^{\circ}\)C. As far as the average is concerned, it falls within the standards; however, the hourly values fluctuate quite a lot and frequently. At the same time, in 99.5% of cases, the T values are below the minimum allowed value of 15 \({}^{\circ}\)C (Figure 8). Given that the study concerns a rupestrian church, the T values are expected to fluctuate frequently and often be below the permissible minimum of 15 \({}^{\circ}\)C. This behavior is mostly normal for the specific cave environment, where microclimatic conditions are influenced by natural factors such as heat transfer and natural cave ventilation [57]. The RH values obtained inside the  
Figure 7: The diffraction pattern shows mineral assemblages of the quartz arenite sample from rupestrian church. church indicate an average of 90.6%, with maximums of 99.7% and minimums of 43.6%; the difference in which the values varied was 56.1%. At the same time, in 99.5% of the cases, the RH values exceeded the upper limit of acceptability, which can affect the integrity of the minerals in the rocks (Figure 8). In the presence of high RH, soluble salts can be transported to the surface of the rocks and, as the water evaporates, they crystallize. The crystallization of salts can generate high internal pressures that can lead to the cracking and disintegration of rocks. In addition, high RH levels favor the development of microorganisms, including molds and bacteria, which can produce organic acids capable of dissolving minerals [58]. A high RH can accelerate chemical reactions that lead to mineral alteration. For example, oxidation-reduction reactions and hydrolysis can be enhanced under high RH conditions, which can damage the mineral structure [18]. Although there are no specific standards for CO\({}_{2}\) levels in caves alone, it is essential to keep concentrations as close as possible to natural atmospheric levels (\(\sim\)400-500 ppm) to prevent the formation of carbonic acid, which can accelerate mineral degradation [57; 58]. Most of the time, the CO\({}_{2}\) values remain within normal limits, with some peaks exceeding 600 ppm, the maximum reaching 834 ppm. However, the variations are insignificant, and the high values are only sporadic. The average value indicates 525 ppm, and the minimums reach 405 ppm on multiple occasions. Approximately 88% of the measured data are below the limit of 600 ppm (Figure 8). Considering the fact that there is no human activity inside, these small variations in the amount of CO\({}_{2}\) can be determined by the respiration of organisms (small animals, microorganisms, or plants), soil and rock interactions (decomposition of organic matter), or the air exchange between the cave and the outside environment [59; 60]  
CO\({}_{2}\) variability can influence the chemical balance in the cave, affecting the formation and stability of speleothems and other mineral structures. In the long term, even minor fluctuations can cause changes in rocks' chemical composition, especially through carbonic acid formation [60].