In Pakistan, blended cements are relatively rare, with most supplementary cementitious materials (SCMs) incorporated directly during concrete production. However, rising demand and the limited availability of high-quality SCMs have prompted cement manufacturers to investigate alternative options for blended cements to cater to the construction sector's requirements. Recent advancements in Limestone Calcined Clay Cement (LC3) have attracted the interest of Cherat Cement Company Limited. The company conducted extensive surveys in the northern regions of Pakistan, collecting 15 clay samples from various locations. The chemical composition and kaolinitic content of the clays were analysed using X-ray fluorescence (XRF) and the furnace protocol method, respectively. To assess the performance of LC3, compressive strength tests were conducted. Comparative samples of control specimens were prepared and tested under identical conditions for benchmarking. Fine calcined clay samples of varying grades were blended with cement to produce LC3. The results indicated that 9 out of the 15 LC3 samples demonstrated superior compressive strength compared to their OPC counterparts at 28 days. Conversely, the remaining 6 samples exhibited only a modest strength deficit, averaging 12%, demonstrating their close potential for optimization to match or exceed OPC standards. The main finding of the study is that all 9 high-performing samples, regardless of kaolinitic content, had an A-S ratio between 0.7 and 1.3, with the best compressive strength achieved at an optimal ratio close to 1. It has also been observed that low-kaolinite clay with an adequate amount of CaO content exhibits good strength development in cement.