With the shift in hydrocarbon exploration, there is a greater emphasis on complex, deep, unconventional reservoirs than conventional reservoirs. This change highlights the importance of comprehending how the depositional environment and diagenetic processes that are influenced by factors such as temperature, pressure, and depth impact the quality of the reservoir and the properties of the rock. This study aims to discuss clay minerals’ origin, distribution, and their control on the quality of the marine-influenced Miqrat Sandstone reservoir formation from the Huqf Outcrop. The objectives were approached using qualitative and quantitative analysis such as the petrographical optical microscope, point counting data, scanning electron microscope (SEM), and the SEM equipped with dispersed energy spectrometer (EDS), Xray diffraction (XRD), X-ray fluorescence (XRF), QEMSCAN system, and the Petrog software. All the methods provide detailed patterns of the variability and the extent of clay coat analysis on the origin and the effect on Miqrat sandstone marine-dominated sediments. The samples in this study were collected from the Huqf outcrop from three measured sections in Central Oman. The analyses reveal the abundance presence of kaolinite minerals in the Miqrat Formation that predominantly resulted from eodiagenesis mechanically infiltrated mud matrix into the intertidal and subtidal sandstone facies, triggered by the tidal forces, which led to the precipitation of kaolinite clay minerals. Kaolinites are displayed as a booklet shape pore-filling the sandstone grains and occluding the pore spaces. Kaolinite clay minerals have undergone a diagenetic process during mesodiagenesis and form clay coats covering the surfaces of the detrital grains. The fibrous hair-like illite clays have developed in some of the analyzed samples, which appear to be transformed from kaolinite claysthrough the illitization process in the presence of𝐾 +and by the dissolution of feldspar and mica grains. The kaolinite and illite minerals are found to coat the quartz and feldspar grains of the Miqrat Sandstone. This results in the preservation of the porosity in the system by preventing the formation of quartz overgrowths, which severely destroy the reservoir quality. The effectiveness of preventing further silica cementation directly depends on the thickness of the clay rims covering the detrital grain surfaces and the percentage of coverage; either partly or completely. This study may serve as an analog for other similar reservoir depositional settings and conditions to investigate the origin and effect of grain-coating clay minerals in enhancing reservoir quality and preventing the precipitation of silica overgrowth.