Imag Silicon Ore[sic] is an ore block added by AcademyCraft. It can be found between layers 0 and 60. It has a mining level of Redstone (like a Iron Pickaxe in vanilla), and will drop the ore block when being mined. Smelting the ore in Furnace or other alternatives will yield one Imag Silicon Ingot, but using a Metal Former can double the yield over using a Furnace.
Do note that although the name includes silicon, it is not considered as equivalent to Silicon, and the ore dictionary name for Imag Silicon Ore is oreImagSilicon instead of oreSilicon.