## 6 Engineering and Mining Implications  
This section will examine the impact of brittleness index methods in evaluating mining and engineering operations. Drillability is one of the most important factors in mining and engineering applications as it directly influences the competency and cost-efficiency of drilling operations. In mining, drillability affects the speed at which boreholes can be created for exploration, extraction, and ventilation, impacting the overall productivity of the mine. The B\({}_{3}\) and B\({}_{4}\) tests are recognized as reliable methods for evaluating drillability [111]. [PERSON] et al. [7] (2022) emphasize that a detailed examination of the mineralogy of a rock offers valuable insights that enhance traditional mechanical testing in assessing the stability of surface and underground excavations. Drillability cannot be accurately defined by a single formula based only on laboratory tests, field studies, geology, experience, or equipment design [112]. Mechanical and petrographic properties correlations can predict drilling rates, but numerical values cannot fully represent the diverse geological factors involved [113]. [PERSON] and [PERSON] [112] (2011) discovered that rock strength significantly influences drillability, suggesting indirect test methods, such as the point load test and Shore scleroscope hardness, as effective alternatives for researchers without drillability equipment. The mechanical properties of intact rock play a vital role in mining and geotechnical engineering, serving as essential design factors for tunnels, rock foundations, and slopes [114]. Some of these characteristics are also utilized as key input parameters in rock mass classification systems. Given that rock properties vary by location, it is crucial to conduct on-site investigations, particularly for engineering applications [115]. The physical and mechanical properties of intact rocks have been instrumental in rock classification for a range of engineering uses, including slope stabilization, tunnel construction, mining support systems, mine planning, and foundation design [116; 117]. [PERSON] et al. [118] (2019) state that the diverse petrographic composition and structural complexity of igneous rocks result in varying engineering behaviors, which can influence tunneling, mining, slope stability, and their suitability as construction materials. [PERSON] et al. [118] (2019) also highlight that the mineralogical composition of igneous rocks has a greater impact on their engineering properties than rock fabric characteristics. Among fabric properties, size descriptors play a key role in influencing engineering behavior. Moreover, fine-grained and basic igneous rocks tend to exhibit better engineering quality and lower roughness compared to coarse-grained and acidic varieties [7]. Uniaxial compressive strength (UCS) is a fundamental engineering property used in the design and planning of civil and mining projects, including dams, excavations, and tunnels. Understanding the UCS is essential for effective project development. Although direct laboratory testing is a common method for measuring UCS, it can be costly, time-consuming, and particularly challenging for soft or highly fractured rocks [119]. The combined finite discrete element method (FDEM) is increasingly used to analyze the mechanical behavior and failure of brittle geomaterials under different loading conditions. It allows for the explicit simulation of rock fracturing, from crack formation to propagation, with the mechanical response controlled by microparameters [56]. [PERSON] et al. [120] (2020) highlight that using the discrete element method (DEM) clearly models particle and block interactions to simulate rock fracture and mechanical behavior, helping to advance the analysis of scale effects, heterogeneities, and confined strength estimation. In rock engineering, the uniaxial compressive strength (UCS) and the modulus of elasticity (E) are key parameters widely used for classifying intact rocks and establishing rock failure criteria.