Multi-resonance (MR) Microwave sensors have emerged as a promising sensing device for mineral-based materials characterization due to their high sensitivity and precision. This research presents a novel microwave sensor for mineral-based material characterization. The sensor’s resonating structure comprises a 3 × 3 array of circular-shaped complementary split-ring resonators (CSRR) coupled with four rectangular defected structures etched around the CSRR array. This unique configuration enhances electromagnetic interaction with the material under test (MUT), leading to precise characterization based on S-parameter analysis. To validate the sensor’s efficacy, simulation-based investigations were conducted on the mining-based materials, including chrome, copper, and quartz. The obtained results demonstrate distinct resonance shifts and attenuation variations corresponding to each mineral, highlighting the sensor’s capability to differentiate and analyze their dielectric properties. The proposed MR-sensor design provides a robust and efficient method for non-destructive material characterization, offering potential applications in the mining industry, quality control, and geophysical exploration.