Non-metallic minerals are found in
A. Igneous rocks
B. Metamorphic rocks
C. Sedimentary rocksD. All of the above

Non-metallic minerals are found in Sedimentary rocks. Non-metallic mineral reserves consist of stone quarries and clay and sand pits; chemical and fertilizer mineral deposits; salt deposits; deposits of quartz, gypsum, natural gemstones, asphalt and bitumen, peat and other non-metallic minerals other than coal and petroleum. These Non-metallic minerals are found in Sedimentary rocks. Sedimentary rocks are types of rocks that are formed by the accumulation or deposition of small particles and subsequent cementation of mineral or organic particles on the floor of oceans or other bodies of water at the Earth's surface.